Are you a baseball fan, out of curiosity?
MLB parks are all different dimensions and even shapes. Grounds crews maintain the local fields differently from each other, sometimes to the advantage of the home team. Colorado plays half their games at an altitude that meaningfully favors offense. Other teams play half their games in climates that meaningfully favor defense. Some teams go 20 days without a day off. Some divisions tend to be more competitive than others. There are injuries — sometimes many of them to one team.
To all those, add: some umpires make more mistakes than others, and some pitchers and catchers are better at adapting.
All of these things aren’t fair. That’s okay. That’s life, and that’s baseball.
Anyway, this isn’t really about overall fairness. Serious accusations of umpires favoring one team or another are very rare. It’s about whether to obsess about every single pitch being called by some mechanical (and so supposedly objective) standard. To me, that misses the whole point. You get 27 hitters per game (unless you win early) and play 162 games per year. If your success comes down to even a handful of bad calls, you were only going to win by chance anyway.