Even if you got a maintainer to commit and release code to disable PoW, you'd still have to get enough node operators to update, which... I doubt would happen.

You may not be able to be so forthcoming about the transition

You greatly underestimate the resiliency of the Bitcoin network.

That would be difficult to pull off. bitcoin code merges are highly scrutinized, and disagreements in blockchain projects just result in forks and new networks.

A better way would be a global ban coordinated among every nation, and even then that would be difficult to pull off.

Difficult to pull off, but they could make it happen.

The earned value would need to transition to the non-proof-of-work favoured network.

Turmoil would take care of the $ value of the forks (crypto confidence is rattled enough as it is)