In the US, probably around 10,000. US Banks all operate by virtue of a banking license issued at the state or federal level. Banks must do as they are told by these centralized authorities or else they lose their license.
Decentralization is about not needing anyone’s permission to participate and being free from censorship. You don’t need good credit or even ID to open an account and no one can seize your funds because of debts, fines, or taxes. Of course validators have their slashing rules, but those are programmatic. Not some judge in divorce court, for example.
> Decentralization is about not needing anyone’s permission to participate
But you do need permission, which is implicitly conferred by following the protocol. It's really quite similar to traditional banks, it's just that the protocol is digital/mathematical rather than legal.