An old classic, but I feel like this quote has a place here. http://herpolhode.com/rob/utah2000.pdf

Yeah, I'm disappointed that sometime in the '90s (or maybe even '80s) we settled on what a "desktop operating system" should look like and we've done nothing new since then. We also solidified on what a "mobile operating system" should look like and that is beginning to stagnate now. Maybe we'll get some new ideas with AR operating systems, but I have a suspicion the designers will mostly just try and port desktop and/or mobile interfaces to AR. We'll have virtual desktops, windows, and app icons floating in front of our faces.

I spend a bunch of time reading old programming manuals from the late 80s and early 90s to try and remember the branches that never made it because the corporations that controlled the main OSs weren’t interested in them. This I guess is post “desktop operating system” but there’s still a lot of variety in how Amiga, macOS, RISC OS, etc. approached that. It’s both a wonderful reminder of how far we’ve come (what was Apple thinking with it’s memory strategy for apps?!) and how much we’ve lost (I love how RISC OS lets you control the resources an app can use for instance).

FYI - what the inventor of the Amiga OS is thinking about these days https://altscript.com