Typical plastic and paper waste is pretty dirty, due to misunderstanding of what can be recycled - anywhere from just thinking anything vaguely paper or plastic can be recycled to places where people apparently think recycling bins are just different colored trash bins (or just dont care). Contamination of otherwise recyclable materials by food is also an issue. Its also not worth much since the feedstocks for new paper and plastic is pretty cheap.
Glass is also fairly worthless, since it needs to be sorted by color to realistically be recycled. Mixed glass I believe is generally landfilled or "up-cycled" into some sort of crushed aggregate for various purposes.
It's also the case that any metal a scrapyard will pay you for is economical to recycle. The majority of discarded steel is recycled.
I've since learnt "recycling" meant more on the line of "collect+transport+sort+ship it out of sight". It was a business like any other, when it was profitable everything chugged along just fine.. as soon as money stopped flowing things gets ugly.
I wonder if there's any opportunity in this. or is it basically wait for some other country to pick up the demand.