It may or may not be harder to hit a 3 inch round ball at 90+ MPH than it is to land on a 4 inch beam while doing a twisting backflip.

But in baseball, you get three chances each at-bat to do that. And if you succeed in a quarter of your at-bats (which again, you get multiple chances each time), that's considered a good job.

As a gymnast, you pretty much have to never miss or it's a huge failure.

I wouldn't get a hit against Justin Verlander in his prime...but at least I'd be willing to stand in there and wave a bat at it in the hopes of getting lucky. Alternatively, I wouldn't even be willing to attempt a 360 degree turning backflip on the balance beam.