[dzikimarian]

You can set up as many as you want, so just register your phone as one and your PC as other. Eg. using Windows Hello. If you loose or compromise one device, you just delete it as a passkey - rest is still working. If you loose all of them at the same time somehow, there's usually fall back to password or some kind of reset process.

[NikolaNovak]

For every account thought, correct?

Like, I can keep all my passwords in a password manager. And then copy and replicate that database however I want to.

With passkeys, I'd need to set up and authenticate additional devices... for every of hundreds of accounts I have? Am I wrong? Like if I have an android tablet and iPhone and windows PC and a Linux PC (as I do) that's half a dozen setups for each and every account? And this is a good thing??

[MilaM]

It's my understanding that passkeys that are created by platform authenticators or password managers can be backed up. That's how replicating your key through iCloud likely works. Hardware keys on the other hand don't support backups by design. You need to enroll multiple keys to have a backup.

> With passkeys, I'd need to set up and authenticate additional devices

This is true, if you don't use a platform authenticator or password manager and only use hardware keys.

[dzikimarian]

As mentioned by other you can use solution, that propagates your passcode credentials across devices - probably most password managers will offer this soon. I wouldn't, because you loose separation in case of compromise of one device, but if you do - it's still on par with security level of today's password managers with cloud sync.

Also you don't really have to set up everything everywhere all at once - passwords still work and you can use phone passkey on PC via QR.