> So we will inevitably end up with some variation of Proof of Stake protocol – where we will simply have to trust some users more than others

Doesn't this defeat the point? I can't imagine a scenario in which a proof of stake system does not become centralized. The average person will want to stake the extra money they have but won't want to maintain a dedicated machine with adequate storage and zero downtime. They will entrust a third party to earn money by staking on their behalf. Thus, you have created a centralized system with a whole bunch of extra complication.