>Whether or not a couple houses in a couple block area, or 1 apartment building all "collude" to do something has very little effect on the competitive market of the massive housing industry.

This is not correct. There are HOAs spanning dozens of miles, with and tens of thousands of homes.

>But large, major players in the education space (each of which enrolls thousands of students), all agreeing together to do something, has a much larger effect, in comparison.

The vast majority of universities offer athletic scholarships, this is not really true either.