University enrollment doesn't drop sharply evenly across all universities. The lowest-desirability universities will go bust while the Ivy League continues to have hyper-competitive admissions and yearly tuition increases that outpace inflation.

In a homo economicus world. They will jack the prices up for the remaining few.

Here in the USA, education at some schools is kind of a luxury good. When the price goes up, the demand increases.

Except it won't because a degree is a gate and people will pay whatever is demanded of them for it. Numbers go up never down.