Simke11

There is Proof of Work and Proof of Stake. PoW needs to do work in order to process transactions and produce new blocks, hence energy usage. PoS on the other hand relies on native coins being staked (locked) on validator nodes, and has minimal energy usage.

PoW concept predates Bitcoin by about 15 years, as a deterrent to denial of service attacks.

It is slow, but it is also decentralized. People don't use it for it speed, but because as long as you own the keys you and only you owns assets in your wallet.

It's not meant to replace relational databases. Apples and oranges.

Blockchain's purpose is decentralized, public, immutable ledger, which also guarantees ownership of assets on blockchain via self custody. No central authority can manipulate transactions that have already been processed.

But dollar has a "trusted central authority" behind it from what OP is saying in some comments and therefore it's ok, even if that "trusted central authority" prints money like there is no tomorrow and causes inflation which then has cascading negative effect on the whole economy.

If he did, he would have found that through the history many thing which we would consider "useless" have been used as a currency and a store of value, including specific types of rocks. If it's scarce and and easy to use as store of value, people will use it for that purpose. Bitcoin falls under this.

USD was backed by gold from 1944.

https://en.wikipedia.org/wiki/Bretton_Woods_system