It's very hard to compare sports in this regards. If we define the reaction time as the time between signal and action, I would say sprinters and swimmers do the purest form of reaction time. It goes straight from audio signal to leg and body muscles. A racket player or bat hitter on the other hand has to process the visual signal to assess ball trajectory, shot selection, then activate muscles.
It doesn't necessarily mean a sprinter has a better reaction time, but that we can get more quantifiable results. Slower reaction times in other sports can be more impressive because of all this extra processing that has to be done.
In track and field sprint start, we basically first defined what is physically possible, and if you do better than that it's considered a false start. One false start and you're out, but the best can still get close to the limit, so when we consider the reaction times of the best sprinters I think we get quite close to what is achievable.