> None of those hypotheticals apply in a company where "123456" was allowed as a password to begin with.
True.
> And if even if they did, which of these two is easier?
You didn't understand their point. The password manager itself locks and tapping doesn't work until you put in the master password again.
The fact that password managers can be implemented badly, doesn't mean we shouldn't implement them well.
Yes, but at the same time we need to remember that "password manager" can only do so much if reducing friction isn't a priority.