This is incredibly short sighted and defeats the purpose of an interview. You’re not trying to trick the interviewee with a gotcha question, you’re trying to find ones with the top skills. Who cares if they can open a modal without JS, when you’re building a front end app, guess what, you’re gonna use JS to open the modal. Building on my point about gotcha questions, I recently had a React interview and 3/4 of the interview was about currying functions in JS, something that’s never ever done in a Reqct app.