The notion that we accept different umpires having different strike zones is not acceptable. There is only one strike zone and each umpire us instructed to call that strike zone. Players should expect to have the same strike zone called regardless of the time or place. The human element is not that players have to adjust to an umpires strike zone, but instead how accurately can an umpire call the pitch.
If we remember back years ago to the Maddux, Glavin, Smoltz era the umps essentially turned the strike zone on its side and called strikes 6-12” off the plate.
Keep the umps and just call the strike zone as it’s written in the rule book. I think having the strike zone depicted on tv has actually made the umps do that better. Instant replay for the close calls on the bases, foul balls down the line, etc shows the umps are usually correct.