What's the problem with those questions?

I wouldn't be surprised to find that in the UK it's illegal to ask a candidate "How do you add to our diversity?" because it could be seen as a thinly veiled way to, for example, discover a candidate's sexual preference - something you are outright not allowed to ask about, except in very specific circumstances[1].

(Also, it's an insufferably pretentious question, even if not actually illegal.)

[1] E.g., it might be legally acceptable for a role in a religious organisation.

I'd argue that they're stupid questions.

What do you stand to learn about the quality/fit of a candidate from the question "why do you want to work with us?"

They could give a 100% bombshell answer and yet not at all fit the role.

The latter is not a question the applicant is qualified to answer. Specifically, "how do you add to <our team>" can only be answered by someone that already knows the team. To me it signals that the recruiter is lazy and expects me, as applicant, to do his job for him.

Sorry, was trying to figure out how the commenter got past those filtering questions.