Edit: I do see that HP made graphing calculators with native RPN in the late '80s, so perhaps they were pushing these for academic markets, although today they seem to be the provence of surveyors.
Random aside: I first learned RPN from my father, a budget analyst, and have used it ever since. RealCalc is an Android calculator app with an excellent RPN mode, if you're curious.
Before Python, I ordinarily used bc (a Unix command that acted as a basic calculator) for simple calculator calculations at my desk. bc was much more popular that the other Unix calculator dc which used RPN. Now I just use python's REPL. I only use a calculator if I'm away from a real computer (which is rare since I carry a smart phone).
It's more cumbersome for a single arithmetic operation, but when you're chaining operations together the stack is very powerful.
It's a lot less abstracted from the way the computer works.
The counterexamples you provide (OSX and Chromebooks) follow basically the same UI paradigms as the Windows machines they replaced (even if some of those might have been copied from earlier Macs). There still may be less overall diversity in the computers we use, even if there are now a number if different logos on the box.