Passkeys are auth garbage. Normal users do not benefit from overly complex auth.

Too confusing for me, I don't get it. How do I record my login info on paper so my family can get in if I die?

Until you lose your device or it breaks suddenly.

I'm not a fan. But what Anthropic SHOULD have done is use plain ol' SSO. Google, GitHub, Microsoft, etc. logins with the option to do this magic link stuff. The third party auth providers would use passkeys at the user's discretion.