Lot of people are pretty decent at bullshit. And they can talk the shop well enough to coast for a while.
On other hand I wouldn't say it would be unreasonable for UI people to setup some basic UI or like that could be done fast. And then do some edits there. Even if it is just copying some toy project. Then again I am not sure what is the current state of fronte-end and how much crap you need to do basic UI.
Yeah I think there is a: "does this person get UIs at all, and like this type of work" filter that gets missed by some of these leetcode processes. Personally tired hearing "this guy ACED the interview, a++++" then they fumble around with the actual work we have to do.