It's not my English or that I haven't heard of upgrades, App Stores don't offer a mechanism to sell upgrades. That's why Im proposing it as a solution.
Yes, and that’s because developers won’t be able to support multiple versions, and they don’t want people stuck on old versions that don’t support new phones and library security updates.
In “solving” the subscription problem, upgrades create more cost, bugs, and exposure for everyone.
It's actually more than that. Many apps have a server component and this requires ongoing revenue and support for multiple versions of the app even if the new OS of the device doesn't break that app.
In “solving” the subscription problem, upgrades create more cost, bugs, and exposure for everyone.