Hi @Smile2u,
I just started following the discussion and I think you are right with respect to decentralization which does only work if people are accountable for their work.
The good thing about the technology we use is that we are able to force actors in the system to have some kind of skin in the game (i.e. they are accountable with the money they lock).
For example, this post here Token design proposal for underwriters to minimize trust in real-world assets describes a possible idea to implement some kind of mechanism for this on-chain.
I personally imagine in the future that asset evaluation and so on will be an active role on-chain that different actors can fulfill and that is rewarded if done correctly and punished if not. Defining what is correct is of course up to discussion.
But as with all networks that only work if enough (rated/known) actors are engaging with it, I think it is reasonable and responsible to bootstrap entities that are able to fulfill these roles at the beginning in a trusted manner and build up credibility before moving to an automated mechanism.
Once the ecosystem is large enough more entities that take these roles will evolve naturally to profit from the protocol.