I don't use passkeys, so I haven't run into it. It seems like that screen would be gated behind entering an e-mail address or username that is already registered with a passkey on another device.

What I'm saying is, I thought I had the right mental model of how passkeys work, after researching them, and that mental model told me you wouldn't be able to log in on a different device without going through a whole procedure to set up a new passkey, which you wouldn't want to do for something temporary.

The mental complexity is just too much for me to trust that if I adopt them, they'll work when I need them. The fact that I got this thing wrong means there's probably other things I'm still getting wrong.

I understand passwords and password managers and even 2FA. I feel like I can plan how to use them right so it all works and I don't need to worry about not being able to access my accounts. I just don't have that confidence with passkeys.