Apps on the iPad will continue to be limited compared to their desktop equivalents until Apple introduces swap memory to iPadOS. Until then, app developers have to code for the lowest common denominator, which depending on your viewpoint is either a basic new iPad 9 with 3GB of RAM or an iPad Air 2 with 2GB RAM (the oldest supported device capable of running OS15)
Apps may be compatible on iPads with lower end hardware but faster chipset and more RAM allows for better features like improved graphics, bigger canvases, more layers, etc.