@Mint_Shock in a case where there is no way to dispose properly of anything, I'd put money on the table that having bins will decrease the amount of litter everywhere.
If people don't have places to throw shit, there's a good chance they'll just dump it there.
@jae that's a cultural thing. For example Japan has basically no trashbins and they just take thair trash back home. Not having bins also has the benefit of preventing them from being vandalized or robbed by animals. That also causes litter in the environment.
This issue is more complicated than "just add more bins".
I'd recommend listening to the 99% Invisible episode or reading it. They explain pretty well why that mentaly doesn't always work.