They're related, but distinct.

Permissionlessness = anyone can participate without approval

Privacy = what you can see is hidden by design

Decentralization = no one controls consensus or can override independent verification

Monero has all three. Bitcoin has permissionlessness and decentralization, but not privacy baked in at the protocol level.

The confusion comes from treating lack of visibility as lack of decentralization. Those aren't the same thing.

Monero has thousands of nodes running globally—and that's just the ones running clearnet. Many more run behind Tor/I2P by design.