My iPad shows that my data is full, but after deleting almost half of my apps, the available space does not change. In fact, as the App data decreases, the “Other” data increases by that much. What’s the deal with this?
iPad mini, iOS 12
A forced-restart of your iPad may be beneficial - as doing so will usually release unused system resources:
Otherwise, if your internal storage is full, your only option is to better manage the storage that you have - and delete unused Apps or unneeded data.
These support pages should prove to be helpful:
About storage on your device and in iCloud – Apple Support
What's the difference between device storage and iCloud storage? – Apple Support
Manage your iCloud storage – Apple Support
How to check the storage on your iPhone, iPad and iPod touch – Apple Support
Clear Other storage on your iPhone or iPad - Apple Support
“Offloading” Apps can also be a helpful method of creating temporary space for a software update.
https://9to5mac.com/2020/01/21/how-to-offload-apps-in-ios-to-save-space-without-deleting-their-data/
Additional information about creating sufficient space for installation of a software update can be found here:
If you need more space for an update on your iPhone, iPad, or iPod touch - Apple Support
iPad Data Suddenly Full
