Crypto is hardly a "sector of the economy". It's main utility right now is lining the pockets of a few speculators.

Traditional centralized ledgering systems do everything crypto does better and with a fraction of the energy use. It also gives governments tools to combat inflation/deflation and manage counterparty risks within the system.

Crypto is a neat idea, but in the end it doesn't really solve anything, and instead only introduces a lot of unnecessary problems.

There are few sectors of the economy whose entire model depends fundamentally on huge energy consumption: Bitcoin's Proof of Work depends entirely on wasting huge amounts of electricity as assurance that transactions are verified. If mining became more power efficient, the algorithm would be changed to bring it back to where it is today.

It has been "done better" in 2013 or so when the first FBA system where created as an direct answer to bitcoins expected future environmental impact and scalability problems.

See https://news.ycombinator.com/item?id=27596590