Not enough validators. To become a validator you have to have millions US worth of BNB. The richest validators get priority. A handful of these richest validators are actually known to be the same entity, reducing the number even further. The chain can, and has, been "paused" by requesting the 2 dozen or so validators to coordinate (to be fair, Ethereum has also coordinated with miners due to hacks, but that resulted in disagreements and a new chain, Eth Classic).
It has all the technology to be decentralized, but ultimately it's not -- or in the least, it's not decentralized enough to survive against nation-state attacks/censorship (though you could probably say the same about Ethereum, Tornado Cash, and USA sanctions).