The last frontier of ejections will probably be discretion when players get plunked at the plate.
:raises hand:
Granted, I didnt grow up a baseball fan and am only now getting into through my kids being in baseball, but coming from less "traditional" sports like basketball I really dont care for the whole spectacle side of baseball. Even in little league you get way more arguing with umpires from coaches and parents alike and its all so juvenile.
I guess I reconcile those positions because I follow the "top-flight" sports I enjoy (in part) as long-running, interconnected narratives. Some of that's on the technical level - like, "this guy played this way last time; how will he approach a similar situation this time" - but it also embraces the personalities involved. The three managers I mentioned were outsized characters in the baseball "story", and I enjoyed their roles - as did they. Each was well aware of the theatricality of their actions, as were the umpires, and there were very few genuine hard feelings.
Earl Weaver, in particular, sometimes ran onto the field bellowing something like "that was a good call! But you gotta run [eject] me here, 'cause I need get them [players / fans] into the game" (though doubtless with more profanity than is appropriate for this forum). Then he and the umpire would yell at each other for a bit, until he departed in (mock) high dudgeon. That was kayfabe, but not purely for the sake of spectacle. He believed - and there's research since that backs up his intuition - that getting his team and fans fired up would be a strategic advantage.
None of that applies / should apply to amateur competitions. I also respect your point of view if you don't watch professional sports from same the angle that I do.
I dont think baseball does a good job of being honest about umpires blowing calls, and to fight the perception of being wrong umpires lean _way_ to the other side to the point that if a batter is even suspected of questioning a call they are ejected. Then, sure, I dont see a problem with the arguing because what else can you do. Its a tight rope, and I dont think they've walked it well. It does feed into the lower leagues though, with completely different relationships (volunteer umps and no replay review), but the same antics.
Instead of doing the hard right thing, baseball does something easier that will be worse for the game. Faugh.