Quantum threat ignored by Bitcoin developers

[Janette014]

‎It's not true that Bitcoin developers are ignoring this threat. There is more to put together by the Quantum computer world to achieve Qday, it's not as simple as they make it sound.

The Quantum are insecure by financial security Bitcoin networks are operating on, so they throw threats to Bitcoin holders. Bitcoin is not the weak security measure as they claim, it's misleading information and according to research, Quantum threats have been in the system for years. It will take more work to break in the Bitcoin private keys and before they can achieve that, Bitcoin developers have upgraded it code.

[ZAINmalik75]

Bitcoin is at least 15 years ahead of banks and the fiat system when it comes to protection against quantum threats. While banks, Visa, Mastercard, and others are only beginning to update their software and infrastructure, Bitcoin will still maintain a major time advantage.Once banks, Visa, and the broader fiat system begin updating, Bitcoin will likely receive a quantum-related BIP soon after, and the community will quickly adopt new quantum-resistant software.

 That is why these kinds of articles should not be taken too seriously, because they are often written by questionable people with hidden motives.

I think we should consider the hurdles, developers can face while upgrading centralized systems and decentralized ones. Probably it is eaiser to upgrade centralized systems, but still saying developers are ignoring this threat, that's wrong, I have seen a lot of discussion on this matter by developers, they are proposing their ideas and other developers are finding loopholes in them, so together they will end up with the best post quantum signature to save the BTC of people who have spent them.

Bitcoin might be ahead of all these centralizations in some way but threat is same to everyone, I heard Google is already preparing for its serives like cloud, infrastructure even their android 17 will have quantum resistance signatures to save it from QC.

[PrivacyG]

Realistically the timeframe to update Bitcoin code and migrate the majority of active users across to quantum resistant wallets and addresses is approximately 2 years. In an extremely optimistic and aggressive scenario this might be feasible in 1 year, but is more likely to be closer to 3 years, as the below diagram elicits.

I do not get this.  If the threat is around nine years away and a Bitcoin upgrade is feasible in 'more likely closer to three years' then where does the FUD came from?  To me, it sounds like Bitcoin is getting ready before the arrival of the Quantum enemy.

Anyway.  If the Internet is ready for Quantum and Bitcoin is not, that is when you have to be worried.  All things that have to be Secure will have to be ready for it before it comes.  And they will, because there is no other way around other than keeping up or becoming the easiest target.

This is why since 2025 we have seen allocators selling down Bitcoin and reducing holdings as the quantum threat to Bitcoin expands.

And this is how you destroy any opportunity of creating this FUD around Quantum Computing versus Bitcoin.  You come with 'expertise' in Quantum threat and then you come with this idiotic claim that Bitcoin has been dropping due to the threat.

What about before the drop when Bitcoin was still under 'Quantum Threat' and it was reaching new Highs?  Was it that people just did not know about the dangers yet?

You are using this as a reason to make people think you say the truth and you are only making things sound like complete B S.

[Outhue]

I don't give a damn about quantum computers anymore, it's been a very long time now that quantum threat as been a thing in crypto space, like a very long time, it's just that crypto is now very crowded than before and every got talking about the quantum threat here and there, if truly this will bring an end to Bitcoin like some people are saying why are bigger institutions investing heavily into Bitcoin? Why was the ETFs ever got approval? That was a dream that was never meant to come true in the past but it's not here, think about it, if quantum threat is truly a threat black rock won't invest a penny in the tech and no single ETFs will be approved.

[Taskford]

I don't give a damn about quantum computers anymore, it's been a very long time now that quantum threat as been a thing in crypto space, like a very long time, it's just that crypto is now very crowded than before and every got talking about the quantum threat here and there, if truly this will bring an end to Bitcoin like some people are saying why are bigger institutions investing heavily into Bitcoin? Why was the ETFs ever got approval? That was a dream that was never meant to come true in the past but it's not here, think about it, if quantum threat is truly a threat black rock won't invest a penny in the tech and no single ETFs will be approved.

Maybe better just pay attention on what will happen on future and don't let yourself don't get an update towards the development of this thread. Although its not good to panic on those attacks since it will just create unnecessary stress for those people got bother on the negative effects they read spread about those quantum threats.

But I don't think it will bring Bitcoin to an end, since maybe the community will find solution about this issue so let's see what comes around in future. Better we prepare about those possibilities and tried to read some updated information on how we can protect ourselves in future.

[tread93]

Bitcoin is at least 15 years ahead of banks and the fiat system when it comes to protection against quantum threats. While banks, Visa, Mastercard, and others are only beginning to update their software and infrastructure, Bitcoin will still maintain a major time advantage.Once banks, Visa, and the broader fiat system begin updating, Bitcoin will likely receive a quantum-related BIP soon after, and the community will quickly adopt new quantum-resistant software.


 That is why these kinds of articles should not be taken too seriously, because they are often written by questionable people with hidden motives.

Oh my gosh probably light years ahead of that. I mean the SWIFT banking system was still running on like copper landlines and nearly dial up circuits until recently and they have become extremely focused now on finally upgrading that system but man bitcoin is on a while other level as far as being flexible and upgradable. There are so many devs that are working on it still even right now as I type this. The architecture of bitcoin and upgrades I believe will be implemented as more and more of these quantum threats become a reality. Right now we are very much so in a wait and see kind of era where we are waiting for the tech to catch up to these we will call them forward thinking articles that google and all these other folks came out with spreading FUD like no other. People are freaking out lol. We have time still to figure this all out. And the wallets that are at risk are the early day wallets anyways right?

[MArsland]

There have been discussions about it by the BTC developers, and it's being at least basically planed.

I place my full trust in the Bitcoin developers, because panicking without a full understanding of the threats is unethical. The developers are far more aware of what to maintain and what to upgrade. So, this panic is good for raising awareness of technological advancements, but excessive panic can be exaggerated.

[Fredletter]

I appreciate all of the replies.

My argument, taken from Edwards and Carter, can be boiled down as follows:

1.  Quantum computing technology (which is advancing faster than Moore's law) that can break Bitcoin's encryption may be at the ready by 2028.

2.  It will likely take 2-3 years to update Bitcoin code and shift a majority of Bitcoiners to quantum-resistant addresses.

3.  Therefore action must be taken now--not in five or ten years but immediately--in order to defeat this threat.

Some have maintained that Bitcoin developers are working on this issue but Nic Carter makes a strong case that the most influential developers are not taking the threat seriously:

https://murmurationstwo.substack.com/p/bitcoin-developers-are-mostly-not

We must act now to counter the quantum threat.  As Edwards states, "We need to see key Bitcoin core developers driving action to a quantum proof solution.  We need to see a BIP with quantum resistant signatures."

[SableTeacup]

yea i think the concern is valid, but the timeline is where people disagree. “2–9 years” sounds a bit aggressive compared to what we actually see in quantum progress today developers tend to move slowly not because they don’t care, but because changing Bitcoin is a big deal and mistakes are permanent. 

[BlackHatCoiner]

The threat is not ignored. There is simply no good reason to rush solutions. There have been many solutions proposed in the mailing lists, and they will continue to be proposed and scrutinized enough so that when the quantum technology is practically threatening (in the engineering sense, not the physics sense), then we can have a few good options to choose from.

On the contrary, the threat comes from rushing to pick a "quantum-safe algorithm" without thorough review and discussion of its tradeoffs.

[davis196]

These two articles (by Charles Edwards & Nic Carter, respectively) on the quantum threat to Bitcoin should be read by all Bitcoiners:

https://caprioleio.substack.com/p/discounting-bitcoins-value-for-quantum

https://murmurationstwo.substack.com/p/bitcoin-developers-are-mostly-not

Hunter Beast's BIP360 proposal has been largely ignored by Bitcoin developers.

Nic Carter:  "There is a pathological lack of concern among the most influential Bitcoin developers."

Charles Edwards:  "Q-Day will almost certainly occur within the next 2-9 years and with high probability from 2030. . .If you legitimately want to maximize the value of Bitcoin now and into the future, you will support the movement of upgrading Bitcoin’s code in 2026."

Preparing for a threat, that might come after 4-5 years seems a bit too much. This looks like yet another "Quantum FUD" attempt.
I'm sure that the Bitcoin developers are aware about the potential threats and risks coming from quantum computers, but I don't see any quantum computers being built right now. The fact that those articles are published on Substack kinda raises some red flags for me. Wasn't Substack supposed to be a platform for subscription-based premium content?

[Satofan44]

3.  Therefore action must be taken now--not in five or ten years but immediately--in order to defeat this threat.

Some have maintained that Bitcoin developers are working on this issue but Nic Carter makes a strong case that the most influential developers are not taking the threat seriously:

https://murmurationstwo.substack.com/p/bitcoin-developers-are-mostly-not

We must act now to counter the quantum threat.  As Edwards states, "We need to see key Bitcoin core developers driving action to a quantum proof solution.  We need to see a BIP with quantum resistant signatures."

You and Nic Carter can fuck off with your FUD. I have given you a negative tag for posting misinformation about this topic. Nobody needs to do anything. Stop pretending like you or anyone else who is panicking own a significant amount of Bitcoin. You own pocket change, and if the big guys are not panicking then neither should you. Surely you random nobodies are the global experts on radically innovative technologies and risk assessment. There is plenty of time to do something, we do not need to rush to anything.

Preparing for a threat, that might come after 4-5 years seems a bit too much. This looks like yet another "Quantum FUD" attempt.

It is, and nobody even knows when it is coming it is all speculative panicking. This 4-5 years from now could turn into 50 years from now. Fusion energy has been away 5 years for 5 decades, and yet it has been making great progress the whole time.  

I'm sure that the Bitcoin developers are aware about the potential threats and risks coming from quantum computers, but I don't see any quantum computers being built right now. The fact that those articles are published on Substack kinda raises some red flags for me. Wasn't Substack supposed to be a platform for subscription-based premium content?

The very use of the wording "Bitcoin developers" makes it clear how OP and anyone who follows this kind of nonsense does not even have the faintest idea about anything in this topic. The developers are not supposed to do anything, developers do not do cryptography research and testing. Developers implement software in one or several languages that they know. Developers are not capable of deciding which signatures are good to implement and which aren't, especially not in a novel field like this.

The people who are supposed to be working on this topic are working on it, and it is not the average Bitcoin developer. They are doing their own job, coding things that are within their scope of competencies.

A quick note on methodology: if you aren’t aware, who controls the levers of power in Bitcoin development is kept deliberately opaque.

Malicious FUD and conspiracy theories again. Wake up @d5000, don't get dragged into every topic without reading the fine print. The author is a very biased scammer, he even lists luke-jr as having moderate influence -- whereas the CSAM obsessed freak has lost any and all influence on the development of Bitcoin.  

[Easteregg69]

Yeah. I think you can put it on the not ignored list. I get drunk since i can't die anymore. Easter and everything.

Tell you man. If the opposition don't stick then i find a better cause. Cheers!

The fact we are here of all the time in the world. Talking about quantum resistance. Choose life then you better understand the miracle it is. As if you buy a share and know where you get the gains from. Some kind of logic proof.

Start questioning religion to get my full attention. I got one. It's not ok to lie about other people but that does not cover the whole spectrum. Out of commandments.

Would I Claim that Max Keiser kiss ass on a dictator to keep his trophy wife at bay? After he rugged Maxcoin? Then what would i say about your President? "Man". I would say that to his face and wait for a reaction.

You tell Max that yobit has a special place for his old fart coin. Some keccak thing. Cheers. After you. Past "take me to your leader" ufo movies. Warming up for ridiculation.

You guys remember the 42' coin. Only 42 coins. Where it stalls. What is better about only 42 coins? You need comparison to make the math.

Tell you man. It's quantum proof if it's not broken. You don't prepare for holocaust. You avoid it. Some broke ass nigga is going down with what it takes.

Colored audiences loves the dirty talk.

[gmaxwell]

I wrote to this Nic person, confused as to why many of his messages seemed to be fixated on me even though I haven't been a bitcoin developer for many years and confused as to why he seemed to be saying there wasn't any progress towards QC hard crypto in Bitcoin even though there clearly is interesting and ongoing progress, and why he was writing about me without ever trying to contact me.  (And were also factually confused beyond that point, given that the penultimate topic I commented on the development list was a QC resistant signature scheme...)

He begged off claiming that he couldn't tell who was working on bitcoin and that he didn't have my email address-- nevermind that a working address is on every commit I've ever made, every mailing list post, on my profile here, and so on.  How could someone have any idea what's going on in Bitcoin without knowing that it doesn't involve me or without being able to figure out how to reach out to a former developer?

I don't see any other conclusion than this is a person who is either unusually and profoundly incompetent or unusually dishonest, maybe both.  Either way their opinions are clearly not worth any time or attention.

In any case, if being able to use signatures that are robust against QC is something you care about for your cold storage-- maybe take some time to kick your neighborhood bip110 promoter in the nuts, because among the other grave harms their proposal would do the protocol it restricts the size of each inputs signatures to far below the size for any existent QC robust signature scheme yet proposed and removes the forward compatibility needed to deploy new signature schemes without a hardfork.

it is all speculative panicking.

It's substantially backscatter from a major con job that has been going on, .. actually at least two with the same premise.  Basically VButerin's old quantum miner scam had a lovechild with Craig Wright's Coin recovery Spanish Prisoner fraud:   There are criminal fraudsters out soliciting huge investments to fund building a quantum computer to steal Bitcoins.  Of course, they're just going to put on a show for a while and then fail.  But for every sucker they get to invest in their idiot scheme, they probably create 99 other people who are afraid of it.  And they're particularly going after parties that appear to have more money than technical acumen.

Robustness against cryptosystem breaks-- quantum or otherwise-- is a prudent and reasonable concern, and it's good to let people decide how to secure their own coins even if you don't share the same security concerns as them.  Keeping someone who wants their coins secured by something other than just ECC having an option would be incompatible with Bitcoin's ethos exactly like the knotzis trying to kneecapp multisig and descriptor wallets.  It's just a question of constructing a scheme that is efficient enough in the right ways that it won't have a big adverse impact on those who don't care about it, and I think progress in that direction looks pretty good.

We shouldn't let people creating panic for their own personal gain have an effect, and by no effect I mean we shouldn't let them foist risky or poorly designed changes or allow them to act as an excuse to not make useful improvements either.

[Fredletter]

Charles Edwards (who will be speaking at Bitcoin 2026) has conducted a thorough evaluation--based on industry experts--of the current trajectory of quantum computing technology (see his article for full sourcing:  https://caprioleio.substack.com/p/discounting-bitcoins-value-for-quantum).  Here are some relevant quotes:

It turns out you only need about 2300 logical qubits (or around 100,000 physical qubits) to break Bitcoin’s cryptography, and five of the top global quantum computing companies are forecasting that capability within the next 2-5 years. . .

It’s here now

Many dismiss quantum computing given its early stage of development. Most don’t realize that quantum computers are already used today and deployed on all major cloud platforms (including AWS, Google Cloud and Microsoft Azure). Quantum computing is also actively used in various industries, including across material science, medicine, defense and finance. . .

Predicting Q-Day

We’ve surveyed Q-Day estimates from qualified quantum physicists, cyber security councils and the top quantum computing companies globally.  Where a major quantum company’s official statement or roadmap includes a logical qubit count in the multi-thousands, we consider that sufficient to break Bitcoin’s cryptography, as 2300 logical qubits is the generally accepted threshold required.

If you collate these industry expert estimates for when Bitcoin’s Q-Day is expected, you will find that Q-Day will almost certainly occur within the next 2-9 years and with high probability from 2030. . .

The Probability of Q-Day occuring

Using this data, we calculate the probability of Q-Day occurring per year using a discrete probability distribution (probability mass function). Each expert’s Q-Day estimate year (or range of years) is treated as equally likely to occur.  So we simply add the probabilities by year, then average them so each source has an equal weight.  The full calculation logic is available here. . .

As the below chart shows, this gives a powerful finding.  Q-Day threat to Bitcoin is not 20 years away as some would like to think.

Bitcoin Q-Day is likely to occur by 2030 (60% chance) and probable by 2031 (80% chance).  Furthermore all of the expert estimates, which includes 6 of the world leading quantum computing companies, fall within the next 9 years.

Note that we haven’t included Quantinuum yet, the current world leader in quantum computing.  In 2025 they achieved 50 logical qubits. Several companies are expecting well over 100 logical qubits in 2026. . .

Bitcoin is slow at Upgrading

Realistically the timeframe to update Bitcoin code and migrate the majority of active users across to quantum resistant wallets and addresses is approximately 2 years.  In an extremely optimistic and aggressive scenario this might be feasible in 1 year, but is more likely to be closer to 3 years, as the below diagram elicits. . .

[j2002ba2]

QC promises are scam, ignorance, or both.
Quantum computing cannot scale exponentially by design.
QC are analog machines, hence noise cannot drop below certain level, no matter what.
That's why the largest number factored by Shor's algorithm (the one needed for ECDLP) is 21, a 5-bit number.
To even have a chance at ECDLP, the noise has to drop 2^240 times, which is physically impossible.
Even 2^100 times noise reduction is impossible.
You could see it by checking the most accurate atomic clock uncertainty - about 2^-56.
All the "quantum superiority" is generating lots of noise really fast.

So the Q-Day will never come, even theoretically, much less in practice.

For all FUD spreaders:
Please show me the full formulas, noise included, which allow for quantum stuff to work as preached.
Well... you cannot, cause there's no understanding, just repetition and blind belief.
Or worse, you discard the noise as irrelevant.
Or even worse, you put magical "error correction", which is totally noiseless, a divine touch from above.

It is very funny, that a major assurance for QC is "capital allocation". Pure scam.

============

Now let's assume, that QC actually works.
That means it could compute quantum mechanics very accurate, fast, and in details.
This would bring abundance, which makes money slightly irrelevant.
After all money need limitations to exist - if everything is available who cares?
So working QC would make all the money less relevant, not just bitcoin.

[BlackHatCoiner]

QC are analog machines, hence noise cannot drop below certain level, no matter what.

Yes, physical qubits are noisy, but don't error rates have to just be below a certain threshold? (Currently 0.1-1% per gate.) You encode one logical qubit across many physical qubits, and the redundancy lets you detect and fix errors.

To even have a chance at ECDLP, the noise has to drop 2^240 times, which is physically impossible.

Where does this number come from? Breaking 256-bit ECDSA requires roughly 2,500-4,000 logical qubits running Shor's algorithm. With current error correction schemes, that translates to a few million physical qubits.

That means it could compute quantum mechanics very accurate, fast, and in details.
This would bring abundance, which makes money slightly irrelevant.
After all money need limitations to exist - if everything is available who cares?

This is just BS. A quantum computer that helps design a better battery or catalyst is still operating within a world of finite resources. Even if we take the extreme scenario that all resources will be accessible in abundance, humans are mortal and thus human time remains scarce; humans will thus need to economize time, and therefore need a medium of exchange to allocate time.

[j2002ba2]

QC are analog machines, hence noise cannot drop below certain level, no matter what.

Yes, physical qubits are noisy, but don't error rates have to just be below a certain threshold? (Currently 0.1-1% per gate.) You encode one logical qubit across many physical qubits, and the redundancy lets you detect and fix errors.

To even have a chance at ECDLP, the noise has to drop 2^240 times, which is physically impossible.

Where does this number come from? Breaking 256-bit ECDSA requires roughly 2,500-4,000 logical qubits running Shor's algorithm. With current error correction schemes, that translates to a few million physical qubits.

I remember reading about ~1700 qubits for 256-bit ECDLP 10 years ago. With more than a billion of Toffoli gates though.

Midway through the computation any logical qubit has to represent 2^256 bits of information. Since qubits are analog, this requires corresponding noise levels - on the order of 0.0000000000000000000000000000000000000000000000000000000000000000000000000001%.
If there's a "meet in the middle", propagating restrictions from both ends, noise needs to be 0.0000000000000000000000000000000000003% or better.
One could try "error correction", but it scales linearly to the number of physical qubits (per logical).

There is a published paper, which takes the noise levels into account. The result is clear - QC fails even in theory.
https://arxiv.org/abs/2412.17269
https://dl.acm.org/doi/10.1145/3736421

Recently, Cai showed that Shor's quantum factoring algorithm fails to factor large integers when the algorithm's quantum Fourier transform (QFT) is corrupted by a vanishing level of random noise on the QFT's precise controlled rotation gates. We show that under the same error model, Shor's quantum discrete log algorithm, and its various modifications, fail to compute discrete logs modulo P for a positive density of primes P and a similarly vanishing level of noise. We also show that the same noise level causes Shor's algorithm to fail with probability 1-o(1) to compute discrete logs modulo P for randomly selected primes P.

[BlackHatCoiner]

Midway through the computation any logical qubit has to represent 2^256 bits of information. Since qubits are analog, this requires corresponding noise levels - on the order of 0.0000000000000000000000000000000000000000000000000000000000000000000000000001%.

Correct me if I'm wrong, but a qubit stores one qubit of quantum information, not 2^256 classical bits. There is a difference between the size of the search space the algorithm explores via superposition with the information content of individual qubits. Error correction operates on individual physical qubits, each of which only needs gate fidelity below the error correction threshold (~0.1-1%). You don't need 10^-77 noise levels.

One could try "error correction", but it scales linearly to the number of physical qubits (per logical).

Not linearly. The threshold theorem proves that if physical error rates are below a constant threshold, you can suppress logical error rates exponentially by increasing the code distance. Google demonstrated this with their Willow chip.

There is a published paper, which takes the noise levels into account. The result is clear - QC fails even in theory.

This proves that Shor's algorithm fails when noise is applied directly to the bare QFT rotation gates without error correction. Cai himself acknowledges the threshold theorems in his own paper:

There is a substantial body of work on fault tolerant quantum computing, starting with Shor's work [39]. Strong threshold theorems are proved which show that in certain error models, if the error rate is below a certain threshold, quantum computation can achieve arbitrarily high accuracy. These are beautiful mathematical theorems.

From what I understand with the help of AI, his disagreement isn't with the math; it's a philosophical claim about whether the mathematical model (SU(2)) perfectly maps to physical reality. This does not seem like "QC fails in theory" at all.

[Satofan44]

He begged off claiming that he couldn't tell who was working on bitcoin and that he didn't have my email address-- nevermind that a working address is on every commit I've ever made, every mailing list post, on my profile here, and so on.  How could someone have any idea what's going on in Bitcoin without knowing that it doesn't involve me or without being able to figure out how to reach out to a former developer?

Lol, you are one of the most approachable people who are "working on Bitcoin".

I don't see any other conclusion than this is a person who is either unusually and profoundly incompetent or unusually dishonest, maybe both.  Either way their opinions are clearly not worth any time or attention.

Both for sure, since the article stinks of people who were involved in both Bitcoin fork scams.

it is all speculative panicking.

It's substantially backscatter from a major con job that has been going on, .. actually at least two with the same premise.  Basically VButerin's old quantum miner scam had a lovechild with Craig Wright's Coin recovery Spanish Prisoner fraud:   There are criminal fraudsters out soliciting huge investments to fund building a quantum computer to steal Bitcoins.  Of course, they're just going to put on a show for a while and then fail.  But for every sucker they get to invest in their idiot scheme, they probably create 99 other people who are afraid of it.  And they're particularly going after parties that appear to have more money than technical acumen.

Excellent point! I have quantum bullshit fatigue here, theymos allows way too many duplicate threads on the same topic as long as it is at least a new tweet by someone.. they are all started by people whose knowledge on these matters peaks at "qubits" and "shor", which have become something like buzzword from the various waves of scam shitcoins. Because of that I have completely overlooked the possibility, no the high probability, that this is going to be one of the next waves of scam. Look, quantum computers are almost here -- invest now to join the race to unlock satoshi's stash, we are almost there!  

Robustness against cryptosystem breaks-- quantum or otherwise-- is a prudent and reasonable concern, and it's good to let people decide how to secure their own coins even if you don't share the same security concerns as them.  Keeping someone who wants their coins secured by something other than just ECC having an option would be incompatible with Bitcoin's ethos exactly like the knotzis trying to kneecapp multisig and descriptor wallets.  It's just a question of constructing a scheme that is efficient enough in the right ways that it won't have a big adverse impact on those who don't care about it, and I think progress in that direction looks pretty good.

Exactly, that is what I have been telling people. No amount of yelling, panicking, creating "urgency" will do anything beneficial for this process. We simply are not there yet, and it is not like there is much that can be done to speed it up. Most people who develop things are not going to be the ones constructing schemes or trying to break them, it is quite a basic misunderstanding -- even some "senior" members here misunderstand this difference. A fairly good, but average, developer (in general, unrelated to Bitcoin Core) probably does not have know what ECC is unless I write it out completely and even then it would mostly be a nod in the style of "I've heard the name somewhere".  

We shouldn't let people creating panic for their own personal gain have an effect, and by no effect I mean we shouldn't let them foist risky or poorly designed changes or allow them to act as an excuse to not make useful improvements either.

Absolutely agreed. Neither big con men like the person in question, nor the users, nor anyone. Panic does not benefit the ecosystem in any way, even if the timeline claims were real -- which they are not.

From what I understand with the help of AI,

Be very careful with this when it comes to complex subject, often it will give you false information. For example, it will tell you that fake public keys in Bitcoin are not possible based on how ECC works unless you ask it explicitly in the direction, explaining how it works, then it will suddenly have an epiphany that completely contradicts what it output to you before. It is an dead output prediction machine after all.

it's a philosophical claim about whether the mathematical model (SU(2)) perfectly maps to physical reality. This does not seem like "QC fails in theory" at all.

Sure, the claim is a bit exaggerated and badly worded but it goes in the right direction. The question here that relates to this mapping to physical reality is that whether physically achievable noise will satisfy the assumptions that are required by fault-tolerant theorems. We simply do not know yet to be sure.