I think it's more about just trying to keep honest people honest. I could think of a dozen or so ways that I could have cheated, some more convoluted than others, but it's enough effort to where I don't seriously consider it, and I did all my exams legitimately.

That's why they make you share your screen; obviously there's plenty of ways to fool that but the goal is to make it so that cheating requires enough effort to where it's probably less effort just to study and do it right.

The proctors are bored college students or similar - you don’t have to do much to defeat it.

They just want to make it difficult enough to catch most.