Passkeys make it feel like the site is trying to get more info about me; it seems harder to maintain multiple accounts with passkeys. They feel worse for anonymity than a password where you know exactly what you're pasting into the site.

Although this isn't true because actually with a password you have to choose how to generate it and everyone chooses different ways.

Passkeys only give a random public key + some capability bits, whereas almost all password logins ask for your email or phone number, for the inevitable reset dance likely facilitated over antiquated email or SMS. Realistically the latter is much leakier.

My understanding is that TOTP and physical security keys both share very little information about you. Perhaps passkeys, being part of a standard that the FIDO Alliance keeps updating, may some day be expected to reveal considerably more information. And the limited number of remote-attestation-approved passkey managers might someday all start start volunteering such information regardless.