How will ETH function after PoS?

Can anyone clarify how ETH maintains integrity after PoS when 70% eth was pre-mined and there is a 32ETH threshold for validating?

Isn't anyone concerned about this? Can't seem to find a solid explanation of how PoS will avoid being misused by large entities like Vitalik, exhanges, banks like GS etc.

Thanks 🙂