WAT!?! Imagine editing an 8k, 3D feature film on an iPad Air. The "handheld" device would end up being a 12 lb behemoth with Gilliam-esque cable madness running to a single lightning port and optional (Red) branded oven mitts.
Pro video editing (and FX, hello) requires massive power, storage, and peripherals - the more the better.
Is there a substantive difference between editing in 8K and in say 720p?
Ie, could I edit my whole movie in downsized resolution, save all the transformations I've applied, then redo them all in 8K on a server someplace for the final product?
Back when REDs first came out, there was a lot of buzz from amateur and student editors who could get 1080/720 proxies of their freshly shot 4K footage almost instantly and hand it off to editors before production even wrapped. This had been the standard for many professionals doing off/online editing for a while, but getting access to that workflow for relatively cheap was the new, cool thing.
There's always an impetus to get higher resolution and quality at the offline stage though, as people get used to improving technology. It wouldn't be outrageous to have a 4k offline now, because people with 4k TVs at home will say "Why can't we? I want to see everything!", even if it doesn't particularly enhance the editor's work.
It would still be done with lower bitrate files, because original 4k material from digital cinema cameras is beyond what most machines are happy with.
No one is editing 3D right now, except a very tiny portion of the industry who are producing specialist films or blockbuster AAA movies with unlimited budgets.
By the time that those become standard and mass market, hardware will be at a place where laptops and iPads can handle the tasks.
4k is very much the standard right now, and almost any Mac right now can handle 4k editing (some better than others) and perhaps even the iPad Pro can handle it in stride.
So the realities of the market don't hold up to your fantasies of millions of people needing to edit 8k and 3D at the same time.
Even in the world of photography, there is no Mac that edits/filters/transforms/renders 30-40-megapixel Raw images without very noticeable latency. For fluidity and efficiency in what I do, I'd gladly take 10x performance over what exists today on the Mac.
Depending on the studio, content is centralized, but for smaller studios, cloud-based storage is prohibitively expensive since they work with raw 8k/4k video files.