Well yeah, no shit. To be recycled, plastic has to basically be pristine, and the very nature of plastic packaging means it usually ends up covered in paint, adhesive, or food. Mostly all three. The first two aren’t impossible to get rid of, but the third is a bitch. Just sorting the clean vs contaminated plastic is tough, but then you also have to worry about the type of plastic. Most varieties are straight up impossible to recycle.