I just noticed that the two biggest bitcoin mining pools already have more than 52.5% of the hashing power (as of 11/12/23 Foundry USA had 27,7% and AntPool 24.88%) and am wondering about the consequences of this. Is it true that if they decide to cooperate and only continue blocks produced by themselves or the other pool, that nobody else could ever again squeeze in a block sideways, because they will always produce a longer chain that will invalidate anything the others do, or am I missing something?
If so, could the others do anything about that? Finding out who created a block is probably not quite possible if they don't want you to and distribute the new blocks over their members, right?
UPDATE: I'm especially interested in what would technically happen if they do that and the hash rate relationship continues for a while. I'm aware that there are human factors in this - e.g. their miners could move to other mining pools if they think they've turned evil. But that could also play out the other way around - if, e.g., governments would try to take control and explicitly order the pools to do that for some real or pretended reason. And if my hunch is right, they would be the only mining pools who were able to make any profit, so there would be a big incentive for miners to move into these pools. But that's just an example - the point of my question is especially what would / could technically happen, as the human factor is rather speculative.