Anonymity (identity) is different from privacy (actions and contents). Perhaps we won't know who you are right now, but we can clearly see balances and transactions on chain. We can also follow them going into the future (do you coinjoin before and after every single transaction? or do you trust every single person you transact with?). Even experts make mistakes.

It's not just about random anons like us either. Actors with more resource (governments, corporations, exchanges, and chainalysis) can do even more with it like inferring who you might be by using that data (amounts, addresses, timing, etc). The longer you use Bitcoin the more data you leave on chain and ever increasing chance of mistakes.