The headset form factor would be far superior in many ways in various aspects of spatial/MR-computing no different than a phone vs a tablet vs a laptop.
It’s not an either-or. The most Mainstream-friendly form factor is neither of these things but smart contacts followed by glasses IMO.
I am of the belief the tech takes off like iPhone, iPad, PCs etc once it’s like sunglasses with all day battery, or better yet a holodeck type deal.
It has to be even simpler and more elegant than that... I've seen the future, and it is not cartoon-proportioned Ray Bans that show you the HUD equivalent of a 1989 Buick Riviera's touchscreen.
iPhone and iPad replaced PDAs, Walkmans, cameras, portable audio recorders, Filofaxes, Rolodexes (there's an anecdote about business manager Ken Kragen, the guy behind organizing the stars on We Are The World, who used to travel with suitcases of Rolodexes), the list goes on for hundreds of miles.
Macs were much slower to pop (iMac was more than a decade after the original Mac). Initially, they replaced typewriters/typesetters (desktop publishing; Aldus Pagemaker was the killer app that made Mac a thing), mixing consoles (ProTools replacing the SSL/Neve consoles), nonlinear editing (Final Cut Pro replacing Avid Symphony), etc.
Right now AVP's prospects are tied too closely to VR, so the goalposts of what it can do have to change... In the 90s the next big thing was one-click purchasing. It was the patent (Amazon) that Apple licensed that made iTunes idiotically easy and addictive to use even when compared to free, unnavigable messes like Napster, Limewire and Kazaa.
Sitting next to a copy of my senior thesis on internet distribution of music, from 1996, I'm thinking the next big thing is no-click purchasing.
When I can look at someone passing by on the street and say, I want those boots, and it finds the manufacturer, sets up the order, billing and sizing info, or I can walk into my bedroom and say "clear the room, now add a Natuzzi sofa that fits that corner" and it finds me the exact product based on what it knows about my preferences and the vibe of the room, all of this sandwiched into a pair of prescription lenses that fit any frames I like, then Amazon is in trouble, and this product will take off like the wheel.
And what a hilarious irony it would be if Apple bludgeoned Amazon by improving upon a patent it quietly licensed from them almost a quarter century ago.