Very few piston airplanes above the entry-level and trainer fleet are normally aspirated. The piston airplanes that fly a lot (mostly in commercial service) are overwhelmingly turbocharged.

Those are the ones that need the higher octane fuel (and the ones that burn the most of it). I could have bought paperwork (the Petersen STC) to allow my Cessna 182 to burn alcohol-free unleaded car gas. That is not available for the replacement engine I installed in that airplane nor for my current airplane (nor any turbo airplanes to my knowledge).