While I understand your frustration, I would quarrel a bit with you calling that iPhone 4 "useless".
Even with the base OS software, you've still got a great music player, a great video player, a multi-function timer/stopwatch/alarm clock, a web browser, a camera, digital maps, a calendar, email, etc.
Main issue is it’s painfully slow if you kept it up to date. I have iPhone 4S running iOS 9. It’s unusable by my standards. It is blazing fast with iOS 6 though. AFAIK it’s possible to break Apple defences and install older OS for this device, but that’s only because of some vulnerabilities and not Apple generosity.
Even with the base OS software, you've still got a great music player, a great video player, a multi-function timer/stopwatch/alarm clock, a web browser, a camera, digital maps, a calendar, email, etc.