Currency and local government can be completely divorced and I think crypto will prove this in the future. I don't think governments will begin to care one way or another as long as they get theirs and taxes are paid. If you can score currency from around the globe and bring it home to a more local domain and pay in to the system where you live, they should have no problem with it.

And the validators, PoS anyway, use very little energy even compared to traditional coin minting.