"The state ... is supposed to be doing the enforcement."
Ehm, no - there are rules which states you have to act, and not wait for the state to come in.
For example you can't leave expired products on shelf, and wait for a customer to complain and call the police to remove them.
Receiving stolen goods is also a crime... and all these sites prosper hosting someone else's contents, often stolen - and the excuse "we are too large to abide to the rules" can't stand.
