I think the broken thing here is that any mandated episode count causes problems. Some shows are better with shorter seasons, and some need longer ones to tell the same story. But even that is all artificial - in any show that is meant to go multiple seasons, the season breaks are nothing more than where a book decides to end before starting the next book.
In the case of Babylon 5, the seasons were crafted to have certain plots and story arcs play out over full seasons, and others play out over half seasons (to line up with the mid-season hiatuses.) This structure would not have worked nearly as well with only 6-10 episodes per season, and needed to be around 20 episodes per season for the pacing to work out properly.
Other shows, like TNG, could have easily been 6 episode seasons since there were seldom any long-running plot arcs. For that show, does it really matter if it had been 7 seasons of 26(-ish) episodes per season, or would it have been fine if they instead released it as 30 different 6-episode "seasons" (with multiple seasons released per year)? Honestly, I think TNG would have been better as a bunch of mini-seasons, as it may have encouraged them to have a little more structure in their storytelling and tried to do more and longer multi-episode arcs (were there any that went longer than 3 consecutive episodes?)
I think a lot of shows don't need these huge seasons, as it leads to less cohesive writing and far more filler. Shorter seasons just work better a lot of times, especially since many places that have this as their primary structure don't limit shows to a one season per year model.