Nice that my daughter, in private school, has to compete for college admissions with the artifically-inflated GPAs of the government schoolers.
Assuming she gets admitted, the bloom is off the rose about 2 weeks into the first term in college. The underachievers can't compete and drop like flies. The college profs and their TAs aren't interested in whether students are "left behind". They are happy to see the class size shrink to a reasonable level to finish the term (quarter or semester). I routinely started with 65 students during the first two weeks of class. By the 3rd week, the class was down to 35. The folks who didn't belong would drop before there was a financial/GPA consequence to remaining in a class they were not capable of finishing.
The students in the college situation are there voluntarily. They are screened (somewhat) for capability. Many are fiercely competitive with sights set on medical school or other professional objectives. The students aren't going to back off the competitive aspect either. It's not anything like a government K-12 with mandated attendance, union teachers and government mandated curricula.