I am in the same boat. I have two ipads, one is probably ipad mini 2 if I remember it correctly and another one is the first ipad pro. Ipad pro is still usable but not fully functional because I cannot upgrade the os and many apps dropped support for old os. Ipad mini on the other hand is totally unusable. I even think it’s in a better shape than the pro one. It feels snappy when navigating. But I cannot use it in any meaningful way.