Privacy is indisputably much stronger on Monero than Bitcoin.

Bitcoin relies on obfuscation, a weaker form of privacy, where the range of possible connections and amounts are availabe to see. Why does this matter? Because someone can use future data to deobfuscate your coinjoin. There is a whole industry dedicated to this: Chain analysis. https://blockworks.co/news/silk-road-hacker-sentenced

Monero hides amounts and recievers via encryption. So, there is no transaction graph connecting senders to recievers. And amount analysis is not possible either.

Ring signatures is the only part that is obfuscation, but it is only for senders. And previous senders are used as decoys for new transactions = compounding anonymity set over time.

Simple example of a Monero transaction:

~6% chance Alice sent $[?] to [?]

With the upcoming Seraphis upgrade ring signatures will jump from 15 decoys to 128 decoys (maybe 256). And eventually ring signatures will be replaced with full membership proofs to do away completely with sender obfuscation.