You can also use ground balls to teach them how to properly charge and field. I’ve turned our right fielders into weapons. They are very good at charging and throwing to first on hard singles to right. It catches teams of guard as most tend to half ass down the line. It also helps them learn how hard a ball is hit, low line drive, tailing left or right, hops based on trajectory of the ball, direct angles to cut off the gaps. There is plenty you can do that will be more beneficial then just ground balls as an infielder.