Does Binance own more than 50% BNB on the market ?
There's a thread that discusses whether does Binance own such an enormous amount or not:
Binance owns 82.69% of BNB . In short, I think Binance does not own such percentages but rather they are in full control of it.
How decentralization BNB coin is ?
With the current situation, it does not contain decentralization at all.
Some might overlook the influence Binance Chain has over Binance Smart Chain's validator set.
BSC has 21 active validators, making it more centralized than most platforms.
This validator set is determined daily by Binance Chain, a network managed by just 11 validators.