I didn’t follow the last part, “because you can anonymously register multiple inputs”. Does that mean you can in fact coinjoin your whole wallet balance (let’s say currently comprised of 10 different utxos) without a loss of privacy?
Discussion
It depends...
Generally speaking yes, but for example if all those 10 coins were created on the exact same day 10 years ago, and all 10 coins are in the same coinjoin transaction, even with 300 other inputs, it is quite unlikely that two or more different users created coins on the same day back then, and are online at the same time now to spend them.
In this case the coinjoin at least adds some plausible deniabiliy, but the most obvious guess is the correct one, so any serious adversary will likely figure it out that those 10 coins belong to one person.
If you're really paranoid, it's best to not even consolidate non-private coins in a coinjoin, Wasabi does this with the "red coin isolation" setting, on by default in the optimize for privacy profile.
Samourai is same or different in your opinion?