> 3D artist, illustrators, graphic designers, UI/UX designers, photographers, videographers, musicians,

Lots of use cases in many of these professions. In particular, there are a lot of professional artists/ illustrators have switched to the iPad. I also know there is an active community of iPad accessories and software for musicians.

Also, while many of the above mentioned professionals can't move their entire workflow to the iPad, quite of few of them have already moved big portions of their workflows to the iPad.

This isn't a zero sum game. For a lot of professionals there is room in their toolbox for multiple computers.