what other ways are there to free up storage?

I have an iPad Air 2 with 16GB of storage with software version on 15.6.1. I’ve been trying to free up storage and unable to for a while now. I do art and editing which can take up a fair amount of storage. I have photos and videos I need so I can’t delete them. I have also offloaded around 20 apps and deleted some that I didn’t need, including some of the basic apps. I deleted data within apps, including almost all GIFs, images, old conversations, and videos sent in messages and it still hasn’t worked. I have even deleted and re-downloaded apps to see if it helped clear some of the data it was taking up. Most of my storage is taken up from the iPad OS, almost half of it and combined with the system data, it is taking over half of my storage. I’ve checked everywhere, including some of the articles and other questions on this website and others, and I only found two solutions. One of them was to buy iCloud storage and from my understanding, it’s for storage from across devices but I don’t think it could help me with some of the apps I have downloaded that I need or the system data and iPad OS which is a bit ineffective. The only effective solution I found is to buy another device with bigger storage capacity but that isn’t in my budget even when turning in my device as well. I still have some storage left but it’s not enough to download CapCut or almost any other apps. Is there any other way to delete storage or to possibly delete some of the system data or iPadOS?