I may reformat this note by compressing in into a larger one or splitting it up further. It’s the best place I have for the moment.
In no particular order:
- Community, social skills, comraderie, networking, friends
- Access to speicfic people, resources, tools, clubs, networks, etc
- This can include the education itself, though most of that is available without attending a university
- Signaling (see Bryan Caplan | The Case against Education); employers are more interested in those with a degree
- External motivation or accountability; some people benefit more from external pressures (e.g. tests, assignments, an actual instructor who looks them in the eye) than others
Why not attend?
- Time commitment; you can drive your own learning faster (see There’s no speed limit)
Note that there’s nothing stopping you from attending a university and driving your own education. It’ll take more work but it’s possible. You don’t only have to learn things that you’re told to learn.