...what's the deal with there being leagues in American sports with no relegation...
Funny, but I was randomly thinking the same thing a few days ago. American leagues are filled with owners that consistently (for ten years or more) produce non-competitive teams, to the point where I wonder if the best minor league baseball team couldn't beat, say, the Seattle Mariners in a game.

The concept of fighting for the right to play in the best-of-the-best league is something, as far as I know, American leagues have never had, and it's likely rooted in the greedy team owners.
I mean, if some of the team owners (like, say, the Oakland Raiders' owner) had to explain to their fans why their team had been relegated, they'd lose respect from many. Subsequently, their suck-ass team would not make as much money with TV deals and merchandise, and the owner would be pissed that the team he doesn't manage properly doesn't earn him tonnes of money.--It's clear that leagues decide that "whoever
has money gets money" rather than encouraging a good competition in sports.
Abasuto said:
Instead of nine 3-out innings, baseball should change to three 9-out innings.
Personally, I love baseball, but I agree that it can be a boring game. The American League made the right step (a long time ago) with the "Designated Hitter" rule because they understood that no decent pitcher would spend any worthwhile time in the batting cage. But the game still isn't ~awesomely~ exciting.
What to do?
SUPER BASEBALL 2020 rules. Yeah. Just like the start of the Arena Football League, effectively make baseball with rules redesigned for making an exciting game. Have giant nets going along the foul lines past first-and-third bases so that the ball bounces back into the field, creating more hits. Legalise fighting the same way that hockey does--with a "penalty box"-sort of thing that would last for a set amount of innings and also cut the team's fielded players down to eight, making the field more-open for hits.
Power armours and androids coming soon, but I seriously would like a more-exciting baseball league to watch.