You can feel as many things as you want but it's quite obvious the reason you are against Dex and are bothered when people mention Dex is just because it's not a feature present on any Apple device, it's not something Apple implemented and endorses so you are against it. I mean its fascinating how quick you were to suggest that Apple's non-existing AR glasses are the solution for what I've described in one of my comments above. That was just ridiculous
Also his point was just to demonstrate that from a practical stand point there are plenty o potentially interested people in such a feature and he makes this point as a counter to you generalist insistence than nobody would really use such a feature just because you look at it from an extremely biased point of view.
There are a lot of great usage scenarios for Dex, from using it for Productivity, Office, Data Bases, Graphic design, edit 4k Videos on a proper big screen to turning the phone into a veritable game console for mobile games or emulated games.
It says in the clip at one point. "It allow you utilize that chipset's power to it's true potential", "It allows you to push the phone much further than you normally would". This was my point from the start, this was the point of the user than first mentioned Dex(as the subject of this thread is smartphone performance), it's a feature that allows the user to take advantage of the phone's SOC true potential.
He also said "I've been doing this for nearly a week and I'm absolutely hooked on it", so there you have it, you can easily make use of Dex for extended periods of time.