Those three categories are pretty broad and essentially cover everything, but my own personal addition would be: becoming aware of "unknown unknowns". A proper university education exposes you to knowledge and worldviews that you previously had no idea even existed.
This is the fundamental problem with self-education: you tend to get stuck in local loops based on your current interests, motivations and knowledge. Sure, the information is out there, but without a proper introduction by an expert, real-world peers learning the same material, and the overarching school structure, it may as well be written in hieroglyphics. External education, when properly designed, should broaden the mind and prepare it for self-education, but without it, you often end up with a fairly limited view of the world shaped by whatever you personally find interesting.
Agree with the unknown-unknowns, the problem is (at least from my pov) that University nowadays mostly familiarizes you with unknown-unknowns that are kind of boring, i.e. stuff that will potentially bring you (the University atendee) financial and societal returns further down the road (I get why they do that, I’m not criticizing them for it, just exposing what I think happens).
Again, from my pov most of the interesting and not-boring stuff that can be studied does not have that many financial or societal benefits further down the road, and as such self-education seems one of the few ways of gaining knowledge about that stuff.
This is the fundamental problem with self-education: you tend to get stuck in local loops based on your current interests, motivations and knowledge. Sure, the information is out there, but without a proper introduction by an expert, real-world peers learning the same material, and the overarching school structure, it may as well be written in hieroglyphics. External education, when properly designed, should broaden the mind and prepare it for self-education, but without it, you often end up with a fairly limited view of the world shaped by whatever you personally find interesting.