The ISS has run many hundreds[1] of experiments, and more are sent up with every launch. It's an invaluable resource, because it's the only (relatively) cheap resource we have for running microgravity experiments which require human input.

They're not the sort of headline-grabbing experiments that most people seem to associate with space (I don't know why they do, most science isn't very exciting), but it's facilitating a lot of science which couldn't reasonably be done without it.

[1] https://en.wikipedia.org/wiki/Scientific_research_on_the_Int...