I can’t think of any features I need or really even want. I use my iPad as a reader device with Internet access so not a heavy user of it. There is no way I could use it to do SW development and that is my only real portable computing need and for that I have my MacAir. I get iPads mostly as hand me downs since I am such a light user of them.
So bottom line, what would induce me to get a new one is if this one broke and I couldn’t find a friend or relative with an old one that I could buy.