I’m currently taking modern algebra/abstract algebra at the university. I’m a sophomore in high school. Would that be something that colleges like MIT would care about? Is that good, and should I strive for even more?
This is good if it fits with the rest of your application, like math-related ECs. But don’t take college classes just for the sake of college admissions, and don’t let them take over your free time to the detriment of everything else.