Steve introduced the iPad as the future of computing, as if it would one day replace computers for most people. Interestingly, it doesn't seem to have happened. In fact, most people who use the iPad as an everyday device will buy a keyboard case that has a trackpad... turning it into a laptop. The iPad, as-is, is good for certain specific tasks but it's terrible for most tasks. Have you ever tried downloading a file sent to you through Google Drive, moving that file into a specific folder and opening that file in a specific app, quickly? Yeah good luck, that's impossible to do. This is the kind of thing the average person does multiple times every day, and you just can't do it on the iPad without going insane.
The iPad has replaced pen and paper notebooks for me, and I like to use it to view PDFs on the go, especially when I can't sit down. For everything else I will always go to my iPhone or my Mac. The Mac is just more comfortable and can do complex tasks more easily, the iPhone is easier to hold and simpler to use for basic tasks. There aren't really tasks that are moderately complex that the iPad is good at. Multi tasking without a working file browser is a joke. Window management on a tiny screen with a large touch UI is a joke.