I havnt managed them directly but I've worked closely with two. One who was pretty much the friend of the owner and pretty useless. One who was really incredible and got a return offer right away and finished a full project while there.

Obviously not all interns are equal. I guess I should have clarified that I meant at companies like Jane Street which have strong internship programs. They have difficult interview processes, pay very well, and interns actually do interesting work.

The high level of compensation for these specific interns reflects their high level of talent.

It's extremely difficult to get an internship at a company like this. These aren't run of the mill interns who are coasting through college and trying to check the internship box.