I can't speak to the specifics of this particular implementation but usually if someone has the login (username + password) to get to totp that user has already been compromised..
If a user keeps their credentials in a notebook and it got stolen, the TOTP check can be the difference between the attacker getting in, and the user being notified and changing their password
Me too, but my day job means I handle a bit of secops, password managers are rolled out as security tools to users operating in enterprises where things like mandating people don't keep their passwords on a sticky note on their monitor is usually step one...
If you have username and password and are able to force the TOTP in the 60s window, the TOTP would be useless imho.