As beginner I thought Hashrate and price has a function.
You mean a
relation?
Imagine voting based on the value of your assets, where Musk has 100 billion votes and 30 millions have zero since they only have debts.
This is an invalid argument. It's true, but so is in PoW too. It's obvious that those with more money can have greater share. This is not why PoS brings centralisation; it's because those who
want to secure the network need those who
are securing the network. In PoW, anyone's free to setup their hardware and start securing, but in PoS, it's down to those entities' judgment if new people can enter.