I once read that business is the art of ripping someone off without pissing them off, and I've since made that a part of my life philosophy because it's very accurate.
These businesses are simply more devious manifestations of that art.
Except in this case the strong person fully disclosed up front that they would most likely take the wallet and run, but there is a chance they would give it back with twice the money. The weak person still made a choice.
Well when you put it that way, we have lots of regulations surrounding gambling for precisely the reason that a significant fraction of people hopelessly "fall for it".
https://www.amway.com/en_US/income-disclosure
https://www.marykay.ca/en-ca/pages/earnings-representation
https://library.youngliving.com/en/us/U.S.-Annual-Income-Dis...
https://www.lularoe.com/lularoe-income-disclosure-statement