The downside of solutions like that, though, is that the site identity is completely handled by a human, so if you had previously saved a password for example.com and someone tricked you into thinking that example.com.uk is example.com, then you will be manually copying over the username and password.

If you use a browser-based manager, however, and had previously saved a password for example.com, then if you were tricked into thinking that example.com.uk is the real site, your password manager would recognise that this is not the same website (bitwarden even warns you if you try to override that)