Have you heard of Komodo? Decentralized exchanges are coming. Not sure if thy trade Steem yet though.
https://komodoplatform.com/decentralized-exchange/
In my view, complete decentralization though is an illusion. Even on Steemit you have the whales or platforms like DTube, Dlive etc. that hold a lot of power - who do they curate and why etc... You will never have a complete decentralization because the nature of the way humans organize themselves is based on always creating some kind of a hierarchy of leaders and followers.
But a more even distributionnof power and wealth is possible. Time will tell though.