Which user/comment are you referring to? The top-level comment? I'm the person you replied to initially, and that's not what I said, so I'm assuming you're referring to something else.
It is my contention that this statement is:
1. Categorical,
2. False, and
3. Categorically false
From the questions and comments across the rest of this thread, the misunderstanding here seems clear: the person I'm responding to did not realize that FIDO2 cryptographically binds credentials to sites.