I dread trying to use desktop apps on a tablet. If I wanted to use desktop apps while on the go, I'd buy a laptop.
If the typing issue was resolved (without adding a clunky, external keyboard) Then there it would effectively replace the laptop in my eyes.
And what on earth makes you think the typing issue can be resolved. Tablets have been around for 20+ years and nobody has solved it.
We will one day have something to replace the keyboard - but it won't be the touchscreen.
In the future, text entry will be via some combination of voice input and a Dasher-like system that lets you gesture-input commonly used words and phrases lightning fast.
Kill your Boddhas. Challenge your assumptions. Or if you will not, get ready to have your mind blown when Apple does it for you.
Also for the young and inexperienced, PalmOS grafitti did that in the 90s and it was a POS.