You are right, these are indeed complex problems, however this is no directed effort against this type of activity.

If anything, having a common platform would make it easier to focus on such things, and I suspect platform owners would gladly cooperate (as they probably would on weeding out underage ads, etc.) -- but in practice, the alternative we see is either going for low-hanging fruit (which these relatively complex operations aren't), or just a blanket effort, like in this case.

All of these hurt legitimate workers far more than the operations you describe.