Passkeys aren't HSMs -- the fact that you can sync them via your iCloud or Google account should dispel any such nonsense. It's fine for Apple or Google to store your keys at your request and they should keep them secure but the model of "here's my key, now don't ever let me look at it but let me use it via what is effectively DRM" is silly.
If a warning message on export "Never share this with anyone. Even someone you trust. Even your IT department. There is no reason anyone but you should have access to this key." isn't enough to stop people giving it away then no security was ever going to work for them. They would give away the credentials that lets them use the key in its absence.