I would argue, that the dividing line lies elsewhere: between creation and consumption.
The average person does not create much, so for consumption, mobile devices are fine (though it is amazing, what a teenager can do to the photos with just a phone). For any creation, be it media, engineering, science, or even just plain old bureaucracy, you still need either desktops, or workstation, and it is going to stay that way for a while. But the market will be a lot smaller than in 90's or 2000's, since all just-consumers moved elsewhere.
A/K/A "generative computing", which has been under attack for a long time. I believe Jonathan Zittrain's written specifically on the topic, though the closest match I'm currently finding is about the generative Internet:
The average person does not create much, so for consumption, mobile devices are fine (though it is amazing, what a teenager can do to the photos with just a phone). For any creation, be it media, engineering, science, or even just plain old bureaucracy, you still need either desktops, or workstation, and it is going to stay that way for a while. But the market will be a lot smaller than in 90's or 2000's, since all just-consumers moved elsewhere.