A browser cell phone doesn't need to be a calculator, a word processor, a typing instructor, a device manager, etc.
A browser/cell phone/Desktop Environment/etc doesn't need to be anything but what people want it to be. I want my cell phone to be a calculator, word processor, typing instructor, etc. And I'm perfectly happy with my browser extensions that share screens and do other stuff that is useful.
People don't buy minimalism, they buy features.