FWIW: I find passkeys to be a very simple and easy to use concept. Simple: it's like a password that I don't have to type in Easy to use: because I use 1Password and just have it installed on everything. On Android, it can be set as the default passkey provider so, even on mobile, I am using passkeys shared across devices. Is this "less secure" because I'm sharing the keys through 1Password. I suppose, at some level.…
OK now say you're on a work/library/friend's computer and you want to look up an account in 1password on your phone so you can type in the password. Passkeys don't support this very basic and common workflow. Meanwhile there's no real security benefit over password manager generated complex and not reused passwords.
I like it because I can use discord on even a pretty untrusted computer without providing it any credentials or access to my passkey, and then later when I'm done I can revoke the session.