Bitcoin futures are outside the system. They don’t actually own any bitcoin. It’s like you are betting that Liverpool will beat Man united, it wouldn’t affect the match and futures don’t really affect the price.
The concentration of bitcoins in a few hands is deceiving. Exchanges and funds like grayscale hold huge amounts of bitcoin but they don’t belong to them, they are custoding it from their small investors. Of course, rich people will buy more than small hands, that’s unavoidable but as long as I have my coin why would I care if my neighbour has 20.
Decentralization and concentration are very different things. Decentralization is about the number nodes and this is important for the security and stability of the network. There is nothing more decentralized than bitcoin.
Wall street are worrying that all this DeFi ecosystem is going to take over and leave them in the street. They are the lambs being slaughtered here and there is not much they can do. It’s very difficult to fight against an invisible (decentralized) enemy