I think over the last 2-3 decades standards have fallen across the board because ideals behind the original purpose of such services, to prevent underperformers from failing out, have morphed into a general administrative goal. I went through college in the early 10s, and there was a very clear implicit bias in all grading - failing students didn't look good for professors, departments, or schools in general now. The result was a consistent sort of unspoken grade padding. The goal of making college accessable to increasingly greater swaths of the population is amicable, but it rests on the again implicit assumption that a simple change of environment allows everyone to thrive equally - but the result is overall reduced rigor and a general watering down of the very meaning of a college degree.
More people may be going to school, but the distribution of talent hasn't changed much, and by the time you're entering college there is a minimum level of intrinsic ability necessary to really grasp technical degrees that no amount of tutoring will mitigate.
but it rests on the again implicit assumption that a simple change of environment allows everyone to thrive equally
This is emphatically not true. The SCS Noonan Scholar program is a very successful program for underrepresented minorities. Initially, they tried just giving money and a seat at an elite institution (Harvard, Amherst, that caliber), and they found that their students failed out of STEM subjects with regularity. So now they offer summer programs where they teach the subject and soft skills, i.e. time management, networking, & so on. This improved outcomes enormously. At Cornell they do the same. For some admits their summer program is mandatory.
You're talking about Ivy League institutions which sample from the tail end of the performance distribution. What works for the cream of the crop, whatever disadvantaged background it may come from, does not necessarily work for the rest. I the concept of distribution statistics is sorely lacking in much of the theory that underpins modern Western social policy, and the negative results are gradually accumulating.
More people may be going to school, but the distribution of talent hasn't changed much, and by the time you're entering college there is a minimum level of intrinsic ability necessary to really grasp technical degrees that no amount of tutoring will mitigate.