Introducing crypto to the monetary system

Crazy is it?

Just had a flash idea, why not get modern, and maybe it wouldn't be as hard to do as it could sound.
So I'm thinking mining and exhanging and using it as the fiats we use already.
Mining could be done in it's dedicated buildings, players could buy these like companies although maybe separately.
Mining costs power, and the realistically minable value would be low, so that it wouldn't replace fiats, but could be used for single transactions between players.
As such crypto couldn't be taxed by the state, but in totalitarian states it could be limited or banned.

Could be freely exchanged between players, the state could also offer exchange in its own exchange market.