Relevant scenes: https://youtu.be/qvrSUwqt6Mw?t=54
Sometimes you know you'll be sitting down for 5+ min and a larger format is just more useful, whether it's for reading with bigger fonts, shopping with more items displayed per page or just for accessing non-mobile-crippled websites like GitHub.
Tablets are like dedicated cameras of the photography world. They might be good at it but it's useless if it's not on you. You don't want to carry a second device. Tablets still can't handle multi-users and you want a personalized experience. You don't want multiple tablets at home. There's no continuity unless there's some drastic change in OSes and we go back to the Novell terminal model of computing. I want to have the exact tabs opened with the text fields I'm halfway through typing. You want a single device to charge. A single device that's paired with the bluetooth peripherals etc etc.
Phones already don't fit in pockets and can't keep getting bigger. Developers are already not making native desktop apps except the heaviest class productivity types.
I applaud developments in this direction.
Leave us engineering professionals (who need workstations to be productive) out of it. Most people have one, pocketable, device. It doesn't take a rocket scientist to understand that, if you work within that restriction, that bigger screens will give people better experiences and thus make for better products.
If it ever becomes feasible to have a phone that unfolds into the size of a TV, you'll quickly find fixed-size TVs become niche products for always-on monitoring dashboards and advertising billboards. People will just unfold their phones to watch whatever show or movie they're going to watch, even if it takes them a couple of minutes to unfold their phone that far to set it up.
As a small tablet, it’s likely easier to carry than a small e-reader or iPad Mini.