Is this really accurate? So 51% attack on bitcoin is around 100btc? Given the advantage of such an attack, won't more users want to do it? Also, won't nation states easily come in on this and attack the integrity of these coins?
Well they don't have to be on the receiving end of the attack. They can be, you know, on the other end.
However it may be the case that a third party holds "owners of the mining hardware" by the proverbial or actual balls. Then the calculus changes.