Most people in my family older than me used to be fine with computers. They're much harder to use and more confusing these days.
Today, the UI is more graphic and more simple than ever before BUT it’s decreasingly connected to the expectations of desktop computing. Many here on HN who grew up and professionally use desktop OSes have lamented the changes (“they’re bringing iOS to the Mac!”) that’s simply because we already had an idea of what idioms and UI patterns to look for. At the same time, we’re generating new patterns that aren’t grounded in historic imagery (and maybe have no research at all) and this is hard for everyone. Especially websites and internet activités.
One example is the “x” to close a window. On a traditional computer, closing the window stops the application and it’s done. Meanwhile, minimizing the app keeps it just shifts the view. On a phone, you don’t really stop the application you just shift view back to Home Screen (you can force close but it’s not really needed). Phones don’t have the same UI at all as windowed devices. So it’s less clear what you’re doing on them. But websites… closing them stops them and today many websites are basically apps.