[jeroenhd]

I have my old Oneplus One as a backup phone, mostly for authenticators and stuff. It's definitely not as fast as a modern phone and the battery is worn down, but it's definitely good enough for messaging, video calling, browsing, and video playback. If I can find an AliExpress battery for it, I would expect the thing to last me as long as my current phone does.

The only problem with it is that the original software left it at Android 5.1, which is unusable in terms of app support these days even with compatibility libraries. Custom ROM support has managed to get Android 11 (still receives monthly updates!) on the device years after Oneplus dropped the phone, but if a bunch of volunteers can keep the phone updated, a company making hundreds of billions of dollars per year definitely could.

I think a significant portion of the population could (and would) still use a reasonably priced high-end phone from ten years ago after a battery swap. If the software wasn't rushed out, I don't see why eight years is that impossible to attain.