I feel like you’re disagreeing with a pointlessly weak version of the comment you’re replying to.
It seems a bit like you are describing university as something only about learning and ignoring the social aspects of it. I strongly disagree.
Firstly let me say that what you have written implies that university merely puts you through some lectures (and maybe some exams and gives you a bit of paper at the end), and you complain that you could learn things better yourself. It would be cynical to think that university is just a book but worse yet necessary for the credential and I will assume that this is not what you think.
As universities are different, let me say what teaching mine provided to frame what I will write below. We began with everyone taking the same courses and over later years there was more choice. Teaching was done with lectures, occasional small group workshops, homework, and 1-on-2 sessions going over that homework. Attendance to lectures (or other teaching) was not required although it was encouraged and assessment was done in exams which included questions from all courses so one didn’t need to commit to certain courses in particular.
While self study was important I think the two key things provided by the university were the small group teachings which gave expert feedback, and discussion with one’s peers which provided non-expert feedback, good sources of inspiration and ideas for things to try, and discussions to build a better understanding. I think this aspect would be hardest to replicate remotely.
The other social aspect was also important: unlike school, you’re no longer surrounded by people who don’t really want to be there and it is an environment where people are particularly similar without all having the same goal. If you go to a sports club, social interactions will be mostly dominated by the interest in the sport. I don’t think it’s a good substitute for socialising with students of other subjects at university.
The least important social aspect was going to lectures although I think it provides a more informal setting than a book to see how the sausage is made (or rather to watch it being made on the blackboard in front of you.)