The free Affinity app, which includes near clones of Illustrator, Photoshop, and inDesign, has made it to iPadOS. The new app supports Apple Pencil Pro, and the only features you’d need to pay for are those that use AI, similar to the way the desktop version of Affinity works. Note that there are a few desktop features missing from the iPad version, but nothing of significance to photographers other than perhaps the Astrophotography Studio.
Get Affinity for iPad on the App Store.