%51 attack not affective anymore?

[Ambatman]

Plus the community would NEVER follow the chain where a double-spend was successful.

  ¯\_(ツ)_/¯

I believe this is just wishful thinking
Bitcoins protocol follows the longest valid chain
Regardless whether there was a double spend.
Except the community would manually come to a decision and make the attack pointless but that's not a certainty.
Ethereum classic is an example that community don't always reject attackers chain.

[ABCbits]

--snip--

Plus the community would NEVER follow the chain where a double-spend was successful.

  ¯\_(ツ)_/¯

By default Bitcoin node would follow chain with most work/longest chain. So each node and mining pool need to manually invalidate/blacklist hash of block used to perform double-spend.

[mikeywith]

By default Bitcoin node would follow chain with most work/longest chain. So each node and mining pool need to manually invalidate/blacklist hash of block used to perform double-spend.

This brings a very interesting yet an old question, are all nodes equally important? what if mining pools, top CEXs, some major wallets and data aggregators like CMC decide to follow the shorter chain that excludes the double-spend transactions's block.

This would cause a chain split, leading to two versions of Bitcoin, and such a scnerio could be reffered to "social layer centralization risk", obviouslly, this requires immense coordination between all large players so it won't happen over a double-spend, but what if it comes as a result of certain governments forcing said entities to change the concensus, do we have enough large community that would stick to the now "weaker, shorter chain and most likely less valuable bitcoin"?  

[dzungmobile]

what if it comes as a result of certain governments forcing said entities to change the concensus, do we have enough large community that would stick to the now "weaker, shorter chain and most likely less valuable bitcoin"?  

It is hard for governments globally to agree with each other for global combined attacks against Bitcoin, it's difficult to do in polarized world now and perhaps more polarized world in future.

Assume it is possible, I don't believe a shorter and weaker chain will become less valuable than a longer and stronger chain but in control of governments. The longer chain is not for Satoshi's vision bitcoin while the shorter chain is.

Assume governments won't be able to completely kill the shorter and weaker chain, it will grow up again but I think with some game-changing technical upgrades for that chain. Community know what is best for them, like how years ago they chose Bitcoin blockchain when it was like an infant.

Many IFs here, so many uncertainty here.

[notocactus]

IMO, nothing has changed since Bitcoin came into existence. The fundamental issue has always been the lack of incentive due to the cost vs. profit ratio.

When BTC first started, you could obtain 51% of the hashrate for probably $1,000—but for what?

That's true and I thought similarly too.

Now or several recent years, Bitcoin has been more valuable but why people did not make any 51% attack?
They did not have enough hash rate.
They could collect enough hash rate for 51% attack, but like you said, what for?

A 51% attack if succeeds, won't help the attackers to get benefit, because Bitcoin value and price will plummet very quickly after a successful attack. Does it worth to spend a lot of budget for the attack and at the end, you have loss.

[Wind_FURY]

--snip--

Plus the community would NEVER follow the chain where a double-spend was successful.

  ¯\_(ツ)_/¯

By default Bitcoin node would follow chain with most work/longest chain. So each node and mining pool need to manually invalidate/blacklist hash of block used to perform double-spend.

Although technically true, but if there is an actual 51% attack, for example by a government entity, then the community of full nodes, the economic majority, and miners will work around those attackers and not follow GOVChain. Because who would really follow GOVChain?

It will be a hard lesson learned about the incentive structure of Bitcoin and how that makes everything stick together. For all the investment spent to attack, it would be absolutely better to merely be a good actor, actually mine Bitcoin, and be paid for doing it.