I'm not arguing that 3* players are all terrible or never end up being good. I'm arguing that the ease of transfers now leads to the best players filtering up. And IF there does become a clear distinction between leagues/conferences, then most will transfer up once they've established themselves against a generally lower level of competition.
5 stars hit at a much higher rate than 4 stars who hit at a much higher rate than 3 stars. So the best recruiting teams will have the supposed best players and hit at the highest rates. But they absolutely won't have all the good NFL quality players in a given year. More, but not all. The issue is what happens after that year when players can transfer