Best practice is to register two keys to every website. Keep one physically in a safe.
With password managers I would say the same basic practice applies. Make sure you have a working offline backup of whatever secrets you hold dear.
There are some sites that only allow you to register a single passkey for an account (AWS Console last I checked) but these should be getting fixed as it becomes more popular
Well, this sounds convenient. Keep the second one in a safe, but register a key to it for every website you use.
Is this a practice we actually believe users will carry out?
I don’t bother with a safe. I have one key that never leaves my home desk and another I have on my keychain. It’s trivial to register the second key when I am home.
Yes it is less convenient than a digital passkey but there is absolutely no way for a remote attacker to compromise it
This part right here is what I fear the most about Passkeys. I've read too many horror stories of people getting banned from Google (often for no valid reason) and losing access to all of their data. It is absolutely insane to hand over all your passwords to a company like this.