This is a point I see a lot of people miss about Bitcoin's power consumption. It doesn't have to use as much electricity as it does, as the difficulty is adjusted to mining capacity.

The reason why so much electricity is being used on BTC is a result of an arms race between miners, not a necessity of the technical specification. Bitcoin would still operate correctly with less mining capacity. What is sacrificed is that the threshold for mounting a 51% attack becomes lower with less miners. But again, the network itself does not need a nation-state's worth of electricity to operate.

No, that's not true. The problem isn't there protocol, it's the security argument. Bitcoin works with three people with one computer each, as long as none of those people has access to two more computers. As soon as one of the three can get three if their own computers, the chain's security arguments are broken. PoW doesn't work on compute, it works on scarcity of compute.

Uh.. any single person who owns more than 50% of the computation can basically mess everything up, unless I'm mistaken?

So, maybe you mean 3 independent parties.. but what's to stop those 3 people from colluding for their own benefit, etc..

Anyway you need a hell of a lot more than 3 to run it.

3 people with electricity, networks, and computers.