Meanwhile, I tried 3 different browsers and can't get past the "enter your name" screen on mobile. Apparently native inputs are too dated to use.
Probably not worth supporting. :) Adding new features and figuring out ways to keep people playing might be much more worth your time.
I was going to disagree because the same countries that really like web games are often the ones using older handsets, but Apple themselves say only 8% of handsets are on iOS < v10: https://developer.apple.com/support/app-store/
Good point about market share though, hadn't considered that.