This might include people working in lumber camps in places like Siberia, "mercenaries" in Ukraine, people in NK-managed restaurants in China, Laos etc, or similar efforts that have been reported on, where the average revenue per worker is likely a lot lower.
I had the same thought - I guess there's additional overhead in paying the in-country proxy and probably also a lot of churn (being found out and fired, and then taking a long time to find another position).