i’ve basically never seen single stream actually work somewhere… every time i’ve looked into the details it appears they just skim off the metal and landfill/burn the rest

If you do it that way, the garbage contaminates everything else, making recycling much more difficult or impossible. Especially for paper and cardboard, which is very recyclable.

Why doesn't everyone already do that if it's so simple?

What "destination" is that? It gets shipped to another country where it's dumped.

(one article picked at random from a search for "recycling fraud")

https://eia-international.org/news/exposed-the-plastics-wast...