A good example of the diminishments in skill and learning can be found in K-12 schools. Students are given instruction that intentionally avoid the rigors of study about subjects like Algebra and Algebra II. Certain groups of "activists" assert that these subjects are inherently biased to make students fail, and lobby for their removal from curriculum.
The results of these actions produce students that cannot read or perform basic math skills, placing them at a lifelong disadvantage.
Similarly, producing pilots that cannot perform maneuvers which might save their lives puts them at mortal risk. It apparently surprises a set of people that flying can present dangers, and that instruction and recurrent training in certain areas will save lives. Certainly it's tragic that accidents in training occasionally take lives.
About 14,000 individuals receive SEL certificates every year. I don't know how many students and instructors die in training accidents, but from what I can gather the number isn't significant. A student that avoids the rigors of training for stall series, engine failure, and other procedures on the edge of the envelope will have no recourse when they're confronted with those situations.