If someone gains physical access to my passkey they can use it to access my accounts (which are also password protected) regardless of whether they have some fancy way of copying it

I think this is a theoretical vulnerability rather than a real vulnerability

Maybe if I was a spy or diplomat or something I'd have to be concerned about Chinese customs cloning my key, but for a normal person if an attacker gets a hold of my key they're probably going to keep it rather than clone it