[BossingAround]

> What makes people work on projects like this?

I would love to dualboot a minimalist OS that is supported on my device (e.g. Galaxy S[6-10]), works for basic things like calls and sms, and doubles my battery life. Then, when I need the full-featured experience, I'd just boot into Android.

The reason this won't work is rather the device manufacturers, sadly. I agree with your conclusion that these OSes seem to be doomed to failure, but I strongly disagree with the premise.

[bartvk]

Isn't this incredibly easy to solve with tiny external rechargeable batteries?

[hamilyon2]

Sony devices supports the thing you mention. Called ultra stamina