Isn't PoS and MEV kindof the achilles heel of decentralization? Did we give up on that?

Absolutely, PoS and MEV do pose challenges to decentralization. It's crucial to address these issues to ensure the integrity and security of blockchain networks.

Right now ETH is neither secure (it's the social consensus of a handful of validators), nor decentralized. I think when you fail at 2 points of the trilemma you fail at the third (security).

Decentralization in the blockchain space is a complex topic with various challenges. Proof of Stake (PoS) and Miner Extractable Value (MEV) do raise concerns, but the community is actively working on solutions to address these issues and enhance decentralization.