Most phones are dockable nowadays it's just no one wants to do it. Single usb-c connection can output the phones video take keyboard and mouse input and away you go. As a matter of fact when I travel I have a portable monitor that is 4K touch screen and has a keyboard and trackpad with it as well. I will use that as a second monitor for my work laptop if I'm working but I'll plug it into my phone if I want a more powerful interface than the phone's touch screen. This kind of thing was touted early on in the smartphone development but I don't believe it's a thing that most people want anymore. Most non-computer interested people are happy to simply use their smartphone with the touch screen interface, most people who have the desire for a laptop or a desktop computer and a phone desire to keep those two things separate. That's why this really hasn't caught on but has been a thing for more than a decade now.
I have no idea how good they are or the quality of them but they do exist outside of a full VR headset. One of the problems is is they have to reach a price point that people, even hobbyists, are willing to spend on them so they cannot be super high resolution displays because that drives the price up a lot. If you want them here they are.
The glasses, there are several options already that are not VR that are simply display overlay. Here is a quick Google search result https://www.cnet.com/tech/computing/xreal-air-vs-viture-xr-d...
I have no idea how good they are or the quality of them but they do exist outside of a full VR headset. One of the problems is is they have to reach a price point that people, even hobbyists, are willing to spend on them so they cannot be super high resolution displays because that drives the price up a lot. If you want them here they are.