What exactly are universities selling in that case?

From an individual standpoint, sure, a student is always well-advised to take charge of their own learning process. But if you can do that, what do you need a university for?

At this point I'm pretty sure the answer boils down to "a piece of paper and a dating pool."

Honestly I wouldn't be surprised if uni for tech becomes a thing of the past. Uni didn't teach me anything I didn't already know from working on personal projects and im fairly sure my public git repos had far more effect in job interviews than uni did. I have talked to others who have finished and they hardly know anything compared to those I know who are self taught.

Pieces of paper that open the gateways to a comfortable white-collar middle class life. At least putatively.

The more expensive ones sell connections that can open the doors to wealth and power.

No, because there's far more to a good learning environment than having good teachers.

I could pretend that I could've learnt the same amount by sitting at home with a reading-list for four years, but there's no way I would have.

I commented on this recently in the context of MOOCs -- https://news.ycombinator.com/item?id=18511176

BaaS (Boss as a Service)

In my experience uni was a place of memorizing endless lists of pointless rules. Better reserve an hour a day just combing pdfs and the website working out which font to use or if the marker prefers camel case or snake case. Just focusing on learning won't get you anywhere because you can lose almost all of your marks because you missed a few of the formatting rules in the complex 40 page spec sheet for a python game of hangman or maybe you didn't comment every single line.

If this is the case, it's exceedingly good training for a number of fields, including the professoriate.