Unique Identifier

[SquirrelJulietGarden]

This is not quite true. There is a unique identifer even from when the bitcoin is minted in the Coinbase block.

When a block is found, say 50 BTC as an example, then each satoshi doesn't have a unique identifier however once those 50 BTC are spent then they have unspent outputs which have a hash. So if someone sends that 50 BTC to 1 person, there is 1 UTXO, but if its sent to 50 BTC then there are 50 different unspent outputs.

And those get all spents and the trial goes on and on and eventually different blocks are combined with one another and its difficult to trace them but its still there.

Learn me a Bitcoin has its explanation on "How bitcoins are used in transactions and how UTXOs are created"

https://learnmeabitcoin.com/beginners/guide/outputs/


Practically, spending all bitcoins you have is rarely practice especially if it is big fund. In addition, it is not a recommended practice to protect your privacy.
General guidelines for sending BTC transactions with privacy improvement.
One of advises is

Don't send round numbers

Don't send round amounts. Instead of sending 0.1 BTC, send 0.10125

[BlackHatCoiner]

All bitcoin are equal in a perfect world but world is not perfect and third-parties will create external metadata to the transparent Bitcoin blockchain.

All bitcoin are equal in the current imperfect world. Proof: You can trade any bitcoin for an altcoin at the same exchange rate as any other bitcoin.

Chainalysis, Elliptic, CipherTrace, and a bunch of others getting rich by selling this data are a proof that Bitcoin lacks fungibility (as a result).

These three getting rich by selling flawed chain analysis results is a proof that people buy into their nonsense. Not that Bitcoin lacks fungibility. If I, as merchant, decide to refuse to accept bitcoin with TXID that starts with "ffff", or refuse coinbase rewards, or any other bitcoin based on arbitrary criteria, I don't make Bitcoin non-fungible. I'm just partially separating myself from Bitcoin.

If you really think all bitcoins are the same value, would you trade your BTC with a BTC that is known to be stolen from an exchange ?

Do you know with certainty that your bitcoin does not come from an exchange heist? Do you make an extensive investigation when you receive bitcoin, to see if they come from illegal activity?

[Zigabel]

With bitcoin these no actual minted coin that will call for the creation of a unique identifier but with fiat there's a need for such especially for the fact that is centralized and for the purpose if regulation since its a centralized currency that has to be in circulation and this identifiers help the regulators get to be able to identify the true ones form the fake that may be counterfeited at some point, with bitcoin its totally different such that you don't need any of such, the only time such can be seen around bitcoin is with the wallet address because they are generated from different wallets and have this identifiers for the sake of differentiation for identification in their various chains as this coin transactions are done on various chains because some other coins have got their block chain identifiers where they are placed and you cannot be sending another coin to a different address and on a different block chain but then this most importantly helps keep the freedom that comes with the usage of bitcoin.

[Darker45]

Yeah, each and every Satoshi has a unique identifier. That's pretty much the same with banknotes. As a matter of fact, that's also the same with stamped gold bars kept in the vaults of central banks and other storage facilities. That's even the same with gold jewelries who are owned by different individuals.

However, I guess identifiers do not necessarily make them non-fungible. A dollar bill with x123 serial number has the same value with a dollar bill with y234 serial number. And they're pretty much interchangeable. That's the same with Sats and gold bars. It's when subjective labels are attached to them that they somehow become non-fungible. But this isn't the rule. If a handful of eccentric individuals find certain value in unique identifiers, then so be it. But they're the exceptions.