I recently visited my alma mater. There is a restaurant/bar right in the middle of campus, which in my time was always an extremely crowded social spot. In addition to the convenient location, meals at the restaurant are covered by the university meal plan, so it's a great way to get some variety from cafeteria food at no added cost. Plenty of students in my time hung out there despite not drinking. When I visited, the place was dead - I and a fellow alumni I was meeting were the only two non-employees there. This was during typical dinner rush hours. There were quite a few door-dashers picking up food, but no one actually coming in to partake in either the bar or the food. During the same trip, I went to quite a few bars and restaurants in the area around the campus which were all packed, but I didn't see anyone college aged at any of them. None of these places were expensive, either when I was in undergrad or now.
Obviously this is one anecdote, but it seems the kids these days just don't like going out to bars and restaurants. I can't imagine 20 somethings have stopped liking food, so it seems the atmosphere is more likely the issue.
What are they going to get out of it? Everywhere you go on most campuses you're hammered with title IX messaging about how interacting with women in anything other than a cold professional way (which rarely results in sex, women don't want that) is harassment and can ruin your life. The only thing left then is getting drunk which is also a good way to ruin your life.
Obviously this is one anecdote, but it seems the kids these days just don't like going out to bars and restaurants. I can't imagine 20 somethings have stopped liking food, so it seems the atmosphere is more likely the issue.