I think baseball dug its own grave with some of the issues brought up here.
If I can bring up two related to the size/shape of ballparks...
Over the past century, major league stadiums have progressive acquired shorter fences, less "weirdness" and idiosyncrasies in their outfield configurations, fewer unique nooks and crannies, and less and less foul space in-play behind home plate.
The upshot of this?
.....
I always disliked that the Royals shortened their field. They used to play to that strength with speed, both in the outfield, and at the plate. Nothing was more exciting than watching Willie Wilson hit an in the park home run. And all the doubles, triples, etc...George Brett --- talk about players that could place the ball when they hit.
It's not the stats like WAR or ORtg that kill it for me. It's the analytics that leads to the in-game decision making. I don't watch baseball hardly at all anymore, but there's little variation in strategy outside pitcher/hitter battle. Manager's are pretty much out there to wear their uniforms and do what their analytics department tells them is optimal. Prospects are ranked on exit velocity and launch angles, not dingers.
Basketball is moving the same way into a very controlled environment where teams stick guys in the corners and try to turn it into an optimal two or three man game.
My suggestion is to create a sport where the parameters are constantly changing. A basketball court where the dimensions are a changing, where point values are changing. Keep the teams on their toes and make them play a variety of styles.
Kids nowadays like watching people play video games rather than baseball. I don't think it's because the kids are stupid, it's because they're smart. They are watching more complex things than we did as children.