If you don't trust your matrix client, why use it at all?

It's also a bit disheartening to see Matrix putting all that "Log in with Google", Apple, Facebook etc so prominently on their login page. The whole idea of decentralised services was getting out of those walled gardens.

Yeah, I would argue it's less about removing trust from the client (which will ultimately get an auth token in addition to secrets and plaintext messages) and more about allowing for centralized authentication and authorization policies.