Tablets and chromebooks have already been around for several years. Why do I still use a desktop for work? Why don't I just ssh everywhere from my eyepad?
Because they suck at making me productive.
Desktops and actual laptops are not going anywhere, because they run fully featured OSs that people can contribute to, not some nasty walled garden of corporate shrink-wrapped ToS turds and ignored pull requests (if you're so lucky to even come within barfing distance of a FOSS component on lobotomy-hardware).
Look, IBM started predicting the death of the desktop, what, 20 years ago? 30? It's not going to happen. Then laptops came around. They're gonna kill the desktop! O noes! Not gonna happen. Ultrabooks are gonna kill laptops! Yeah, maybe.. Depends on how much they wind up resembling good laptops.
Starts to sound pretty familiar after a while.