“We need it” deserves a follow-up question. Maybe more than just one!
A requirement can survive several meetings without anyone asking why it exists.
I question things that sound settled: the integration, the approval step, the feature that “every competitor has.” I also question my own favourite solutions, although I’m considerably less enthusiastic about that part.
Every assumption we implement becomes something someone must use, maintain and eventually change. So I want to know: Who needs this? What evidence do we have? What happens if we leave it out?
Sometimes there’s an excellent reason. Sometimes the person who originally requested it left two years ago, and we’re still designing around their preferences.