This is a shame to see - it's understandable that there are some technical challenges in it, but it does seem possible (via a mutual auth handshake) to introduc

This is a shame to see - it's understandable that there are some technical challenges in it, but it does seem possible (via a mutual auth handshake) to introduce portability. Kudos to you for arguing the case though! Before "cloud keychain" (i.e. software-backed, like Apple's implementation), your only "safe" option was to have 2x hardware tokens, and try to keep one off-site, but still accessible enough you could enrol it on all the sites you use. I fear with "cloud keychain" Webauthn, we are heading for a world where getting locked out of (or banned from) your "FAMNG" account will lock you out of everything else, to an extent we've not really seen before - no access to your synced keychain secret will prevent you from logging in to everything. Physical tokens remaining interoperable should give technical users an insurance policy against this, but without some kind of portability (i.e. pairing hardware webauthn keys), I fear it won't be practical enough to keep users safe, and independent of the keychain providers.