Mining is more decentralized now than it was when Chinese pools had 60% of the hashrate.

We're also rolling the Stratum v2 protocol, which will considerably improve the decentralization.

https://braiins.com/blog/stratum-v2-bitcoin-decentralization

Let's not forget that the entire point of "proof of work" is to waste electricity and waste electronics in persuit of making pointless calculations until one is randomly correct. What a great system!!

The point of PoW is to make money hard to create, unlike state money (fiat).

You could say gold, silver or basically any store of value use PoW too: they require a considerable amount of time and energy to obtain. If you could just use dirt as money, it would be worthless as anyone could produce some effortlessly. It's the basis of sound money.

Bitcoin currently uses about 85TW/year of energy for its mining. Estimations for the traditional finance system seem to be around 2000TW/year. Factoring the amount of transactions, Bitcoin is about 50 more efficient per transaction (accounting transportation, paper and coin production, datacenters, energy used by banks). Its energy usage is also independent of the amount of transactions, so it becomes more efficient as the number of transactions grow.