People keep saying that China was accepting recyclables. They weren't accepting them, they were buying them. It's hard to make a case that it was all just trash when somebody was paying for it.
It wasn't all trash, but a significant portion was. Without expensive sorting machinery, recycling is generally only profitable with extremely cheap labor and a disregard for environmental damage caused by tossing the unprofitable stuff in the nearest dump. What was profitable for 1990s China would not have been profitable for the US.
And that's the thing. Recycling everything might be affordable but when skimming the best and tossing the rest is more profitable, operations like that will squeeze out operations that pay some of the high cost of proper disposal. "Externalities are externalities"
Essentially, I think you can make an argument that private enterprise can not do recycling properly since collecting money for taking the junk and then disposing of the junk as cheaply as possible is going to be a better business model. And hiring an agency to watch the private contractors is going to cost less than having a state agency do it themselves. See the company that was paid to recycle all the CRTs from the early 2000s and wound-up just storing them.
Just as much, as recycling exploded, regulations wound-up pandering to upper-middle-class consumers and allow plastic to be marked as recyclable, using unsorted recycling and similar things that kept consumers lazy and ignorant. Of course, this contributed to no real recycling being possible even as a few years it seemed universal.