In broad strokes, MLB's supposed parity problem is no problem at all. I remember going back over the 10 seasons between 2012-21 during the lockout last spring, and in that time only 2 teams were never what you'd call a championship contender. One was Philly, who missed the cutoff by one season after winning 102 games in 2011, and the other was Miami, who almost doesn't count because they've rarely ever even tried to be a real major league franchise. That's not the case in the NFL, the supposed parity model, and the NBA couldn't even dream of that kind of statistic.
The issue isn't that no team can ever dream of being good, it's that in each individual season, several fan bases essentially know they're hosed before it starts. But I don't know if there's any finances-related solution to that.