In China, you can't get that much fuel in local gas station to fill up a truck. That is just one of many things you can't do in China. In the name of safety. Keep asking that question will probally end up with fewer and fewer things we can do.
It's already an established industry with human resources. If you read news about how these scam factories operate in Southeast Asia, their cost to use real humans is even cheaper than running a 2.8T model locally for scams. You don't need genius-level intelligence to run scams. Maybe we tend to overestimate how smart people are.