The problem for me is I am on Linux devices and I can see this being a solution that will start to lock people out of there accounts if they don't have an approved device...
I doubt there is no passkey solution for Linux.
Might not have a bundled one (maybe it will be added), but you could use something like KeePassXC, which is open source.
This will be an interesting passkey test. Much has been spilled about the complexity of passkeys for normal users but in many cases you can just not use them or they’re just tied to your personal smartphone for your personal Gmail/icloud
Amazon is an account that is shared by many between household. Will this cause user confusion