Indeed, assuming a very powerful attacker then limiting them to weird technical attacks is unimaginative.
'just have to catch some miners, gather them up on stage and shoot them in the head. (Or more realistically put them in prison).
Don't hypothesize weird technical attacks when boring things will do.'
https://buildingbitcoin.org/bitcoin-dev/log-2012-05-17.html#l-642Even outlaws don't have that much use for an outlaw currency. Actually
destroying bitcoin would be very hard but depriving it of almost all of its value would be much easier for a major nation state attacker. But why would people want to do such a thing? -- in general, they wouldn't.
That is overt. People will see and know what happened. Some of what was posed could be done covertly. No public bad actors, no acknowledgement, just oh look
BTC was around for this many years then that happened and it and other cryptos went away. People would point fingers and everything else but w/o proof it would all be speculation.
I seriously do not think it could really happen in just about any of the ways listed, but that does not mean that it can't happen some way.
-Dave