I can't believe these comments - passkeys are pretty easy to understand and most platforms allow you to add multiple. Not enough for truly one-passkey-per-device, but if you use a password manager that syncs passkeys, or hardware passkeys it's fine - it's easy, quick, and more secure than any password can ever be (mitm resistant).
I think the confusion with passkeys comes from that fact that everyone wants to own you so you have to be mindful if this passkey is being stored on the OS, the browser, sync'd between devices through google or apple, etc.