Wasteful mining and the promotion of price instability are the core aspects of bitcoin. No one will even consider changing PoW mining and fixed supply.
The problem is in changing the fundamental properties and trust. Trust is the main pillar of any currency. If you would start changing those properties, then people will start to ask what fundamental rules will be changed next and they will lose their trust in the system. That is the reason why wealth needs to move to more developed currencies that already have more developed core properties.
And in all probability, wealth won't rest on those new and better currencies forever either. There will be more new and better developed cryptos that will again flag the start of another phase.