How short term? The NCAA is I would say firmly entrenched as the place to go for athletes looking to go pro. You likely wouldn't just outright steal all the players necessary to create a successful league in the first season, it would take years of convincing kids that your league can give them the same chance to go pro as the NCAA and your league wouldn't have the benefit of having been doing it for decades like the NCAA. You'd have to convince ESPN, CBS, FOX etc. that they should give your league air time when they've been making buku bucks off the NCAA for years.
I think it'd take many years to make that kind of change in the perception of the NCAA compared to a new start up league in fans, players, pro teams, tv stations, etc.
Also I think that schools need players just like players need schools, I just think players get the raw end of the deal because people say they get education and room and board paid for them but that education that is the major part of their "payment" has a very subjective level of value depending on the person and how much they care about it.