First off, Bitcoin is only pseudonymous and not anonymous by default.
I might slightly disagree on this coz even we are under codenames/false names/tx's/addresses this also fall that we are anonymous for most coz no one can tell if you're behind that address to one another. Anonymous is not knowing the identity but knows what it looks,smell or appear in any sense while anonymity on the other hand is not knowing completely. So I guess neither of this, the decentralization of bitcoin will fall onto, but who cares?
It's not an opinion, it's a fact. Sure all we see are just addresses and tx IDs, but those data can easily easily be traced back to a personal identity(may it be an exchange account, or an IP address, etc); especially if you don't take extra privacy precautions. Hence, pseudonymous. This has been addressed a lot of times already throughout the years. I suggest looking deeper into it.