It seems like decentralization is just another word. It doesn't exist. I will not name people, but I have seen witnesses who misuse their power by upvoting those who do oil-messaging to them.
About whether someone is VIP in the eyes of Top20 or not, the evidence is for everyone to see. Justin bribed them and overtook steem.
Decentralization on paper is equivalent to communism on paper.
It looks good only on paper, not in the real world.
I'd say that reaching 100% decentralization is difficult. There seems to always be a part that is centralised. For example the frontend https://hive.blog itself is centralised, someone has to own it, if the server behind it goes down it goes down. Ideally, we would want a frontend that is powered by multiple servers, owned by multiple users etc...
That's why Hive developers need to find a solution to prevent this, things like one user should not be able to vote 20 witnesses to the top.
It's too early. Maybe you are right, maybe you'll be proved wrong in the future.