There is nothing else like NCAA football or NCAA basketball anywhere in the world in the sense that other countries do not have college athletics that millions of people care about. There are many reasons why those two sports are so popular and lucrative and other minor leagues are not, but any list has to include 1) the fact that most of the country is connected to a major school athletic program in some way, either directly as an alumni or as a family member or friend of an alumni, and 2) the NFL and NBA leave money on the table by not doing the minor league themselves.
Now college sports wants to break that fan connection, while also make it easier for the major leagues to step in front of them and become the sponsor of the minor league.
Or do you think that all those ACC, Big 12 and PAC 12 fans, plus all the G5 fans and others interested in college sports, will drop what they are doing every Saturday to watch Missouri/Mississippi State or Iowa/Minnesota because now all of their teams have been made irrelevant?