The onscreen keyboard works great for typing both in portrait or landscape. You just have to get used to it. Keyboards are mostly a hastle to drag around/setup and they break.
If I was on my laptop I would ssh in on a slightly larger screen.
You can definitely do word processing, spreadsheets, the web, programming, everything on a $100 (or even $50 in some cases) Android tablet. I haven't used my laptop at all in like 4 months.
So I would get slightly used Android tablets and give them out to kids.
I actually don't want to buy another laptop or desktop because I know it will waste electricity and it seems primitive.
The next major shift for me will be to full-time VR for work, which will use Google Cardboard or their new 6dof thing (I might wait until the Android for VR OS comes out next year). But that is still going to be on a phone..