This topic has been discussed so rigorously and the conclusion is always that no reasonable state or adversary would spend so much resources on trying to stop something so insignificant. Unless you're looking for any sorts of profits, 51% won't work. You are bound to spend a few billions in both the hardware, facilities, electricity and various other miscellaneous costs for such an insignificant attack. The money could be better used in other areas. You COULD diminish the confidence that people has in Bitcoin but another crypto would simply rise again and the cycle continues. Not to mention that ASICs are not that easy to obtain or operate in bulk.
Yeah, it would be really pointless to even make an attempt at such a venture. 51% attack topics used to be a thing in the early days of the forum but stopped being one as more and more people got into crypto. I don't see why any organization or country would want to do something like that. Considering how much it would cost to execute such an attack. So much efforts for very little reward.