You gave one suggestion, which was based on inter-personal trust. This removes a major benefit of taking part in the Ethereum ecosystem. If it became a widespread way for people to take part in Ethereum's staking mechanism then yes, Ethereum's consensus would effectively be based on interpersonal trust (which is something that the developers have gone to great pains to avoid).

I gave two suggestions - join a pool, and run a pool.

Both of which (essentially the same thing - "be in a pool") require trust, which destroys a key advantage of Ethereum (and cryptocurrencies in general).