I am an android / windows user. After several years I splurged for an expensive brand new iPad specifically to run music apps such as behringer deepmind (which integrates with their synth).
Couple of weeks later iPad silently installed some os update. Half my apps stopped working! They were apparently incompatible with the current OS and I needed to "contact app developer for an update". Which as you point out isn't going to happen.
This is extreme user-unfriendly BS, but apparently par for the course in Apple Land. Eventually I gave the now-useless iPad to my wife. Lesson learned, though not sure what lesson it was. It's hard to run apps?