IMO Fundamentally it’s two different ways of deciding who gets to play in the top tier..
- The franchise system that the US uses for all its domestic sports. Where the league decides which teams should play where, and moves teams from one region to another and adds teams, as they see fit.
- A league system with relegation and promotion. Where teams drop down to the division below when they finish bottom, and are promoted when they finish top.
But yeah it’s a bit of a sidetrack