What I'd like to understand is why the majority of sites that allegedly supoprt passkeys do not let me store them on Yubikey hardware but instead are pushing into "cloud" passkeys. That's what is triggering my spidey sense about the whole scheme. If they are so great all around and vendor neutral why is everyone pushing me to store my keys in some "cloud" password manager? If I'm going to the trouble of setting up passkeys I want to be in control of them across all my accounts. That means my own hardware dongle. Not some cloud vendor's pinky swear that they'll take care of them and let me use them on my terms.