I think the problem with the portal is you either get players who did not live up to their hype out of high school, or players that are just seeking more NIL money. Those seeking the former hope a coaching change will develop and expose the potential, those seeking the latter need to tame the ego.
A coach needs to be able to leverage the portal in both directions. The portal means you can more easily discard of players who are not working out, but if you do, you need to replace them. That said, how many game changers have come out the portal? I think the portal will always be more a depth play.