The transfer portal completely eliminated JUCO players moving straight to high major programs. Even CuJo, who played at Indian Hills, had to go to Buffalo first to get a chance to play P5
I watch a lot of juco ball at Iowa Western, over the last 20 years, there has been less and less d1 talent coming through for all teams at that level. In the late 90's/early 2000's you'd see 3 or 4 high major kids playing every night. Now, you see a handful all season. The talent just isn't what it was at that level. Mostly because of summer ball allowing coaches to scout more kids than ever, there just isn't as many slipping through the cracks.
The only negative I can see the portal having is that kids who left d1 programs used to drop down to juco to get their stuff together for a second chance to get back to that level. Now most of those guys just drop to a lower d1 program to fill spots created by the portal.