Pretty sad all the people getting mad about an optional opt-in feature. I think this is pretty cool. If it’s free to use with my existing unlimited plan I’ll probably use it regularly, otherwise if I have to pay more I’ll probably just keep using ChatGPT since I already pay for that.

Yes and no. You’re correct that if someone compromises your proton account, the 2fa does nothing. But in the other hand, if someone were to acquire your credentials some other way, they may still only have the username and password, and maybe the time-dependent 2fa code. So I would argue it’s better than no 2fa but somewhat inferior to using a separately authenticated 2fa app/device.