Strangely, the iPad is marketed towards people who don't need the complexity of a desktop computer, yet the unintuitive, constantly changing tricks you need to do to get something simple and basic done are not suited for those very people. If I was going to choose the ideal computer for a non-tech savvy person, it would definitely be a Mac and not an iPad. Learn things once, write down how to do it, and it's not going to change significantly. Things work as you expect them. With the iPad, you have all these hidden gestures and constantly changing locations for things, and constantly changing apps. The YouTube apps keeps changing how you close a video, for example. Once you had to swipe down on the video, then right to make it go away. Then they made it go away instantly. Then they re-introduced the original gesture. You pretty much have to constantly keep up with now apps are doing things because it keeps changing. Dropbox keeps changing its shortcuts, sometimes removing features, or hiding the "open in" menu within the "share" menu that's hidden in the "3 dots" menu. Why is opening a file in the "share" menu? It makes no sense. On a Mac, things don't ever change so drastically.
The iPad can do most things a computer can do, but there remains a handful of very important things that pretty much everyone will need to do every once in a while (downloading a ZIP, converting a file, etc) that the iPad has no solutions for. So just for those handful of things, you have to keep your computer. But if you're going to keep your computer, the iPad is not a replacement, but a companion device. Which is a luxury, and you can very well get by with just a computer and no iPad. Not the other way around.