We're already there. Emmanuel Clase is under investigation for fixing pitches and can't play right now.
I don't love sports betting in general, but I really hate betting on short term events like specific pitches or a strikeout. There is way too much incentive to fix.
Legal sports betting via app which turned gambling into a casual activity for hundreds of millions of new players. These apps made a market that previously placed 4 billion in bets to 125 billion. This is very new.
Their rise and market is so large that only 5% of sports bets aren't placed through one of these apps.
Legalized, league-approved sport betting is new-ish (2018). And sports betting has grown 25x since then.
Not sure if I agree with OPs take though. It might just be that baseball is a traditional, conservative game and they are hesitant to change it. maybe that's why they're just using robo umps for challenges, and not for every pitch, which would be easy to do and would further the all-about-betting theory.