> It seems that the vast majority of software I'm hearing about is targeting iOS, Android or embedded systems.
That's because you are mostly interested in those things.
> Is anyone working on a software product that (a) targets a non-mobile, non-server device and (b) is for sale, as opposed to Open-source?
None of that is "opposed to Open-source". Anyway, if you use Windows or macOS, then open your platform's "app store" and take a look at literally any category but "free (as in beer)".
Yes. There is a whole world outside of your bubble.