Because the strike zone is supposed to change with the height and stance of the hitter. It would work really good for inside and outside, low and high is where it would get tricky. But it isn’t like the umps really change their zone too much for shorter players vs tall players now, and pitch track doesn’t look like it changes either. So maybe just come up with a standard rectangle height above home plate.
But I think that would mean a lot of 2 hour 13 inning 1-0 games with the relief pitching now, at least for a few years. The zone that is called by the umps looks like a crooked oval depending on lefty/righty hitter, with basically no actual corner calls called correctly.
Freegards
Sensors on the uniforms.