The US is the only country in the developed world that hasn't ratified the Basel Convention [0] and the US exports close to a billion tons of plastic waste to other countries per year [1]. The trash you see building up in third world countries is in large part from the United States, not from those countries themselves.
That leaves 35 million tons, and with only 5% being recycled, there's plenty of plastic left to go into 'rivers, oceans, everywhere'.
[2] https://www.smithsonianmag.com/smart-news/the-us-recycled-ju...