I don't think it's a terrible system at all and I love the idea of punishing owners who have found a safe, warm rentier space of being the Washington Generals, collecting the check, and being insulated from all consequences.
Thought experiment: take all of recognized association football, all nations that are accepted (start with about the top 20 national league systems), all levels, worldwide, and have all revenue shared between all teams. It doesn't have to be exactly equal, there can be a gentle curve based on results and tier. Reward winning... but not insanely. Punish losing or dropping, but not lethally. So, say, ManU winds up with a revenue sharing check that is 2x a tier 2 contending team, 4x a tier 3 contending team, 2^(n-1)x a tier n contending team.
That preserves the merits of pro/rel. If managed correctly, Havant & Waterlooville F.C. can someday win the EPL title. Likewise, if managed poorly enough, Liverpool can someday fall to tier 8. But dropping from tier 1 to tier 2 won't bankrupt you. In fact you'll go into relegation with a leg up on the other teams because you will still have talent geared for tier 1, and your revenue sharing check might be half but it won't be 1/100th of before so you can still pay your players. You won't make as much personal profit but you lost, f-ck you, you shouldn't. Own smarter.
Fixed leagues are boring and they create perverse incentives for owners who are already predatory rich f-cks. If you want to take all teams public and give them to the citizens of their cities then we can talk about fixed leagues. Until then, pro/rel is better.