Couple of points on the portal:
1. The vast majority are moving down, not up, and I'd guess most of them are happy with their increased playing time. They might be less happy if they see the team they left had an injury or suspension that would have meant more playing time if they had stayed, but generally they'd be moving to a situation where they were wanted.
2. The portal has put a head count on transfers and makes it seem like it's exploding now, but teams were losing a couple of players a year before NIL.