Well, not all of us. I hit the site on my PC with its 28" screen. I don't even look on my 10" tablet. But have you not noticed that with each new model of Smartphone the screens get bigger and bigger? I would think that's because more and more people use them for more and more things. Watching a movie on a 6" screen seems a bit pointless to me, too, or sites that seem to use a 2 pnt font! One maker is even bringing out a folding screen.
BTW: When I had a website, the tracking data told me exactly what people were using to view it. Even to the OS and search engine. It was surprising to see how many people hit my site using so-called obsolete devices. The world is a big place and it's not all up to speed.