The existence of feedback loops very much doesn't imply a stable equilibrium. Actually, any system that is not overdamped will necessarily not reach an equilibrium.

Or maybe the equilibrium is that no country bans it, and PoW currencies don't die on their own due to lack of financial rewards, and PoW artificially inflates the demand and therefore price of energy, leading first to widespread economic issues, then widespread ecological issues, until there is no one left buy pizza from with your BTC. Very compelling equilibrium.

Is there any forecast of where the equilibrium happen? Say, if you're in a 1000-people closed society where cryptocurrency is the only thing used to buy stuff, what's the economic calculation for the long-term energy consumption? Seems like there should be papers about that...

> It’s a system with feedback loops, it’ll eventually level out at some equilibrium.

An equilibrium doesn't entail that it's a sustainable point, or that it's actually providing value when you properly account for all externalities.

I think you're right. I phrased my argument like all PoW must necessarily collapse once they get too popular, and that may not be true exactly.

E.g. if Bitcoin had no block rewards, then the income from transaction fees alone might provide a more reasonable ceiling for miner activity. Users will only pay fees that make sense vs the utility they get.

However, for Bitcoin that's not the case right now. The combination of high price and block rewards provide an enormous subsidy for miner activity. (Some back of the envelope numbers elsewhere in this thread[1].)

And if Bitcoin gets banned, all PoW will likely get banned, so it doesn't matter if other PoW systems can behave better.

[1] https://news.ycombinator.com/item?id=29373653

Seems like he’s insinuating a global ban will occur.