20 years ago was 1995. NS32k was long dead then; National retired it in 1990 when it was only six years old. Even when it came out, it was kind of an underdog compared the the already-five-year-old 68k, which was already powering the SUN workstations and went on to power any number of Sun competitors plus the Lisa, the Macintosh, and the PalmPilot.

ARM has been around at this point for 30 years, and yes, there are incompatibilities from one to the next. But it'll probably be around in some form for another 30 years.

And, yes, your Windows binaries will probably still be runnable ten years from now, and your Linux binaries probably won't be.