The helpful part would be for the huge company to give users visibility and an easy choice, not your simple "delete everything" strawman The data doesn't "belong to me", that entirely depends on the specific app/type of data (and this concept of a few kbs of very important stuff I've carefully changed in the app's settings menu and would even like to track in vcs vs all the other junk is also largely missing, though that's also on the app devs)