Doesn’t matter. Your applications could choose not to include certain iOS versions anymore. And then you’re SOL, even if you’ve paid for the app but now the online component doesn’t work because they changed their APIs.
Depending on the app, do you really expect companies to devote X resources (maybe even a full, separate iOS team) specifically to maintain a version of an app for older devices?
Maybe that's feasible for the larger tech companies but not the smaller ones.