Most people are on phones now, who uses computers if not for work?
But I guess one could argue using phones would be the same, but even then my personal experience is that most people don't know much about phones either.
Delete: maybe tap and hold, then three dots or an (i), maybe swipe right/left/either.
Close an image: probably pull down from the top but not always.
Undo: Shake the phone like an etch-a-sketch???
Whereas Outlook Express, for example, looking at screenshots, had a big red X with Delete written underneath it in the toolbar. And your mouse had a physical button dedicated to stuff that's now hidden away behind long-press or swipe or the (i) or whatever.
I expect that this includes people with disabilities (physical, learning) that prevent computer use, and that it’s a large number of people?