Yes,, it’s made for cheating and griefing. But does that mean that’s its only practical use? Absolutely not!
Some features I use all the time, but only in private servers and singleplayer, include the radar and freecam. The radar allows you to see all mobs in your general area, so you know if something is sneaking up on you. Freecam allows you to fly around the map without actually moving, which is an absolute godsend when looking for caves and such.
Also, I'll admit, sometimes it's just fun to cheat!