So? Software demand is driven by the tasks software need to solve. Whether those tasks involve human interaction or not is surely irrelevant for the demand for software?

Software demand isn’t driven by the number of copies that can be duplicated across servers.

It is driven by distinct use-cases.

Sure! I doubt that most use-cases involve direct human interaction.

Depends on what you consider a "user". You're a user of this website too, presumably running on Linux.

Good point. Everything has free software somewhere in the system. Most content is served using open source software.

But almost no-one uses Linux for general computing because open source requires configuration to be usable.

I'm on Manjaro Linux and didn't configure anything :D But, I know what you mean.