> whole gestalt of what you do on a computer is now one big programmable surface

Emacs-effect. Use it long enough and everything becomes "one big programmable surface". I've been in that modus operandi for years. Emacs is my "control room", I don't necessarily do everything in Emacs, but for sure it converges all into it - everything flows through Emacs. I control my WM directly from the REPL inside Emacs. I can grab a content from a tab in my browser - I have access to my browser history, and all the tabs, I can switch to any tab, close and re-order them. I can grab a text selection on the page, I can extract entire readable corpus of an article while ignoring all the irrelevant fluff - banners, ads, buttons, etc. It works even for js-rendered content (React, et al.). I play all videos controlling them directly from Emacs - even though the video itself is playing outside, in mpv. I still can pause, change volume, fast forward, speed-up, extract transcript, etc. All without leaving Emacs. That's pretty useful when taking notes. I can grab any text I see on the screen. Even if it's in Slack.app. Why, If I can read it, there's no reason why Emacs shouldn't be able to. I can grab any region on my screen with Flameshot, it goes through Emacs, runs tesseract and OCRs the text out of it. Useful when someone's screen sharing in Zoom. This was all possible before LLMs. Now, LLMs running in Emacs can do some crazy, wild stuff.