Install the Beta If You're Dealing with iOS 12 Problems
If your iPad is really struggling on iOS 12, you might want to give the iPadOS 13 beta a shot.
Yes, the beta is plagued with issues, but there's also a chance it improves your device's performance.
Apple's betas have been known to iron out common problems like UI lag, abnormal battery drain, connectivity issues, and random reboots.
If you're having a hard time on iOS 12.4 or another version of iOS, iPadOS 13 beta could work wonders for you.
If you don't see a significant improvement, you can always drop back down to iOS 12.