A few years ago, there was a mini-trend of showboating about how many universities that accepted you. It is not difficult to apply to dozens of schools, with the assumption that you are not going to attend, but only to post that you got accepted on social media. Type A parents encourage this since it reflects on them as well (must be a good parent if the kid got accepted to 20+ universities).

Universities have caught on to this trend, and use other heuristics for acceptance like "has this person ever emailed us or visited the campus?" and not just taking applications as the only input. So acceptance rates have started to reflect this. Sorting through 1000's of throw away applications to find those who might actually want to attend.