Re: Is this really useful for anyone?
Yep. Solution looking for a problem.
I can remember my first analogue mobile, nearly 30 years ago. 8hr battery life (so long as you didn't use it much) and 8 hrs to recharge. 10 minute charging would have been great.
But now? My Android Honor thingy can run for a couple of days on a full charge (depending on usage) and fully recharges from 20% in under an hour. I charge it at night.
And it doesn't need a separate charger - just a standard USB-C plug.