Does Proof of Stake make web3 efficient enough to work?

The core tenet of web3 s decentralization. Proof-of-work is expensive and slow but is decentralized and permissionless. Proof-of-stake means the richest nodes get permission to add blocks. That makes it permissioned. In PoW you need to control 51% of CPU power to dominate the chain, in PoS, you need to control 51% of tokens which is easier and cheaper (if you get in at ICO stage). To answer your question, it make it more efficient over PoW, but violates the core principle of web3.