I'm not so startled by the number of systems that assume you have a smart phone - most adults do - but am startled by the number of systems that assume you have access to a keyboard/mouse/monitor.
I have PCs at home and at work and a laptop that travels with me. I use these computers to do things like filling out forms, shopping, composing emails, reading PDFs, filing taxes, tracking my calendar, and otherwise interacting with businesses and governments that use computers.
A shocking number of my friends and family do all of these things on their smartphones. They're not impoverished, they might have a PC at work but none at home, they might even have an old laptop they haven't booted up in years...but they'll suffer through side-scrolling a PDF or typing on a ~3" square display (the top of their 6" display, with the bottom used for a touchscreen keyboard).