> Centralized trash sorting seems like a much more efficient solution

How is this supposed to work? Sorting trash into many containers takes me a little more time and effort and pretty much exactly as much energy as putting it all in one place. It also keeps the materials from mixing (that is, becoming dirty). How would it help to first mix it all, compress it together (which is pretty much required to keep transport efficient) and then sort it again?

Even if you want to use a sorting machine, would it not be better to have presorted ("richer", in mining lingo) input material streams?