> Compare this to ENS, where if you get 51% control once, you can give yourself 100% control for perpetuity, because you can execute arbitrary code on the smart contract.

Maybe I don't understand crypto well enough, but since everything is in a public ledger, can't 'everyone' just decide to go on a hard fork right before the moment the bad actor took control, thus de facto invalidating all transactions after that point? If that is true, in a way the power over a crypto resides in wherever (rather, whatever fork) the majority of users believes it resides.

Yes (actually, it would only have to be a soft fork), but that would require serious coordination. Ethereum has done it before, so it's not literally impossible, but it would require the whole of the Ethereum network to do it, not just the ENS people.

If it did happen, it would raise serious questions about the nature of the decentralization of Ethereum, and how suitable it is as a deterministic platform to build stuff on. Then again, it already happened and nobody seemed to really care.

If Ethereum is willing to fork over X, what's to say they're not willing to fork over Y? And the answer to this question is probably to do with "the big guys with the money at the top like X, but not Y". So much for decentralization.

Yes, in fact this is exactly what happened when a hacker found a bug in a DAO that allowed them to steal tens of millions of dollars. The outcome flies completely in the face of the idea of decentralization, censorship resistance and "law as code". But don't let that get in the way of the ponzi scheme.

https://levelup.gitconnected.com/how-ethereum-reversed-a-50-...