I've owned a smartphone for a decade. I think a decade should be enough time to really go over a learning curve and become a master of something... but here's the problem. I've typed relentlessly on touchscreens for ten freaking years yet I still make typos - more so than ever. Ten years should be
Just make phone with a removable back that can have a slide out keyboard attached.
It kills two birds with one stone.
Removable / expandable battery, and keyboards for those that want them.