I'm most familiar with MacOS for this. (Still haven't jumped ship to Linux yet.) You can assign the channels to the speakers as you please in the OS audio utility, FYI. And then you can select a lesser output format if you want autopilot downmixing. For example, if you set the output to 4.0 quad, the center and Lfe channels are mixed into the front L/R. (And it expects those to be channels 3 & 4 from the source file respectively.) Some media players can be a little weird though. Everything still needs to be tested and vetted.
The standard channel order is what it landed on for good or bad. It only requires action when you decide to do something different. But there ARE outliers as I mentioned.
I remember visiting someone who had the 2 fronts, center, and one of the rears randomly scattered in front of the room. Literally random everything like one half turned sideways. Some people truly have no interest whatsoever in reproducing sound as it was intended. Not even in stereo. Not even in mono. That's why I think much smaller steps are needed before we start telling people to hang 4 additional speakers from their ceiling!