By comparison, I’ve lived and traveled all over the US, cities and rural areas, beaches, forests, etc. Litter is rare. Where you will find it are freeway underpasses, neglected urban or near-urban waterways and railways: places where people aren’t really “supposed” to go, and are therefore loitered in and rarely cleaned.
There are many areas where the US lags Europe, but in my experience when it comes to litter, we have far less of it.