Probably because these caveats and weird behaviours are platform-dependent, not really the passkey’s fault.
Passkeys really are not any more difficult to explain than 2-factor authentication. Anyone who’s currently been able to actually create an Apple or Google account and successfully navigate their devices up to a passkey screen will be able to grok how it works.
People around here really ought to stop thinking users are complete idiots. Hell, you don’t even to scroll that far to read people calling users “normies” for crying out loud. What is this? High school?