I don't understand any of this logic: you can trivially run new versions of gcc on any distribution you want, and you can trivially use new versions of gcc on n

I don't understand any of this logic: you can trivially run new versions of gcc on any distribution you want, and you can trivially use new versions of gcc on new distributions (which is sane) to target arbitrarily-old distributions. I routinely use bleeding edge compilers to target pretty ancient systems, and have for decades now... like, the entire point of gcc is that it is easy to compile it to run on whatever crazy system you have and then it should be able to target whatever other crazy system you have as long as you have a sysroot for it (which is of course somewhat easy to obtain as it is generally equivalent to whatever system you would have used to compile "natively" for that system).