RE BCIs: Totally agree. We need to figure out a way to allow people to "think-type" 20,000 distinct inputs. This is how we can totally escape the keyboard.
RE VR: I understand your skepticism, but people significantly underrate the quality of text that can be achieved in VR, even on today's hardware. Simula in particular has put in a lot of work in text resolution optimization (something that earlier VR Desktops failed completely at). This makes me able to use Simula for hours at a time, even on the old HTC Vive (2016 hardware). I won't lie and say it is equally impressive as a 4K monitor is today, but it's definitely usable and allows you to garner the other benefits of VR Desktop (10x more screens, 10x the size, 10x the focus/work immersions).
If you have an HTC Vive/Vive Pro/Valve Index, I can help you install Simula/give it a try. Contact me at george.w.singer [at] gmail [dot] com if you're interested.
I feel like we got so close to that with Continuum on Windows Phone, but it was far enough away that it never took off. Drop your phone into a USB-C dock, and you'd get 1080p/1200p video out with a Windows 10-esque UI (desktop, Start menu), keyboard/mouse support, plus an additional USB-A. In practice though, the limitations (range of available apps for WP was mediocre, you couldn't run apps side-by-side on the monitor, some apps didn't implement a full screen UI) made it frustrating.
Or the other way around with using tablets, phones, chromebooks etc. as thin clients, so whatever you connect to the monitor does not really matter.
Laptops and tablets would no longer be distinct factors for mobile, because they'll be replaced by always-worn high quality AR glasses, which run off a phone in your pocket (as Apple's glasses are rumored to be) and project virtual screens into your view of the real world. The AR space may be shared by multiple users for public signage, advertisements or virtual pets and fashion, à la the anime Dennou Coil. [0]
Physical keyboards/mice/trackpads will probably still be around because I haven't seen anything to fully replace the need for tactile feedback, unless someone comes out with sensory gloves.
At home we would put our phones into a docking station for more processing power and to connect to a giant physical screen and sound system.
[0] https://myanimelist.net/anime/2164/Dennou_Coil