Actually when a PoW ban is passed, it will ban all crypto using PoW not just BTC.
Right now BTC & LTC are the main one, doge has a roadmap to evolve to PoS.
So really only 2 coins out of the top 20 on cmk will be banned.
Want to keep PoW, find a way to lower it's energy waste.
New PoW algo that blocks ASICS, or regulate how much energy PoW miners can use, or only mine 4 hours out the day.
Any of these allows the wasteful PoW to continue, or just do nothing and wait for the Ban to end PoW and the coins that want to hold onto it.
Or
Continue in the Delusion that proof of waste is not going to destroy a power grid, and pray nothing happens because the governments are just being mean to btc.
Mining bitcoin or coins using POW is to make a profit, that is to create benefits and contribute to the development of society, so I do not consider it a waste of energy. The bitcoin mining industry is like other industries, they consume energy, but they all create value for human use, so they cannot be called wasteful. Bitcoin is not profitable for you, but it has benefited many people and helped many people have better lives, and when people's lives are better, it will improve society.
I don't know what world you're talking about, but the world I live in still doesn't have too many countries banning POW, because they know the real benefits of using bitcoin.