Compare the Centralization Risks of Proof-of-Work Mining Pools versus Proof-of-Stake Validator Pools

In Proof-of-Work (PoW), centralization risk stems from a few large mining pools controlling over 51% of the total hash rate, potentially enabling a 51% attack. In Proof-of-Stake (PoS), centralization risk arises from a few large entities or validator pools controlling a majority of the total staked coins.

Both mechanisms face centralization, but PoS risk is more capital-based, while PoW risk is hardware and energy-based.