That's could be part of it, but for AR, drawing or (hand) writing, reading long-form text, applications that involve putting your device where a piece of paper

That's could be part of it, but for AR, drawing or (hand) writing, reading long-form text, applications that involve putting your device where a piece of paper or a paper notebook might go (lecterns, music stands), anything that requires or is made better by orientation sensors and accelerometers, basically anything involving a camera that's not video conferencing, plus probably some other stuff I'm forgetting about, the format and hardware capabilities of an iPad make it significantly better than a laptop. Laptops are better at some other things, but if you do very much of the above you're probably gonna have a tablet, too. If you don't do much of what laptops can do that iPads can't (mostly for software-limitations reasons), then replacing the laptop with your tablet might be a viable approach. You can't really do the reverse without a bunch of extra hardware (admittedly, you do need a keyboard and some kind of pointing device for the iPad-as-laptop-replacement thing, too) or just carrying two devices.