That's not comparable because you have no way to look at lottery tickets before you purchase to try to figure out which ones are more likely to be winners.

A university on the other hand does get to look through the applicant pool and decide who to admit.

That sounds clever!

But buying more lottery tickets does in fact improve your odds of winning. So your comparison breaks down because it undercuts your point.

The fact that you have no a priori knowledge of what is a winning ticket is not the case with college admissions. It's actually the complete opposite! You have a great deal of prior knowledge and odds of academic success. So, the lottery is a poor comparison in that regard.

Further, the lottery will always bankrupt you because the tickets have overwhelmingly negative expected value. In the case of education, every single study on it indicates extremely positive outcomes. So in fact, adding more seats and getting more students in college, all else being equal, is likely to have a positive economic outcome. If $1 dollar lottery tickets paid out $3 on average, the more you buy, the richer you would be. So again, the lottery is a poor comparison.

What if someone else does the work of validating that 10% of the tickets are most likely winners, you’d be a fool to pass on that.

If you buy enough lottery tickets you're guaranteed to win.