If TLS was broken, I would always be able to get your password by just removing the hashing from the login page. I'd also be able to modify all legitimate requests, and be able to obtain your genuine login tokens for any site.

That requires an active attack though. Yes, that’s always possible if TLS is broken, but it takes more work and is detectable. (Not saying it’s easy to detect, but it’s detectable in theory, where passive sniffing is not.)

If TLS is broken, you lose all message authentication, rendering tampering entirely undetectable.

Passive sniffing requires the same attack vector, and the idea of an attacker only utilizing passive attacks makes no sense.

The point is that additional hashing designed for the premise of "broken TLS" fails the thread model test: It is pointless, as the only time it is applicable is when everything is fallen apart.