> As soon as the stakes rise that far, however, I reach for a whole-ass Unix environment with a shell, a filesystem, and a stateful process model.
I don't understand what you mean by "reach for". Don't, for example, Linux desktop users have all these things at hand all the time? For me it would take much more effort to set up a "notebook" than a virtual environment.
For you, sure, but for someone that lives and breathes notebooks, running jupyter notebook and going to localhost:8888 already happened, so it's opening a terminal that's the extra step.
You would start the Jupyter application, then use a browser to go to localhost:8888 :)
To start the application, you would typically use the start menu on Windows or the Dock on MacOS. Alternatively on MacOS you could point the Finder at the /Applications folder, then start the application from the Finder window.
(This is not meant as an endorsement of notebooks.)
I don't understand what you mean by "reach for". Don't, for example, Linux desktop users have all these things at hand all the time? For me it would take much more effort to set up a "notebook" than a virtual environment.