It comes down to individuals who respect the environment they or others are in, or don’t.
I was in a federal campground in the eastern US a few years back, and pulled into my campsite to find it littered with orange peels, apple cores, onion skins, juice boxes, chip bags, etc., and the fire pit with burned cans and other garbage in it.
As I walked my dog, I saw the same kind of litter in other sites, including at one a pair of heavily soiled women’s underwear on the ground.
I took pictures and showed them to the young woman in charge in the office, who said that she had a couple of guys who reportedly were inspecting and cleaning up campsites after people left.
Apparently, not.
Then there was the state park, also out east, where a group had been gathering, and when I pulled into my site there was what appeared to be a weeks worth of animal feces on the ground at my site.
One of the best weapons we have against this kind of thing these days are the cameras on our phones, where if sites have been registered for or permits issued the problem can be tracked to individuals and addressed in some manner.
The state park referenced has since required that sites be inspected by assigned camp hosts before being released to the next camper.