I only had time to scan read this, but your basic premise is deeply flawed, IMO. "skin in the game" means you have a vested in interest in something doing well. It almost always leads to more favorable decision-making.
Even your examples are off-base. I believe you get much better outcomes typically when you hire a lawyer or a doctor who is your friend than when you get some rando. That extra "skin in the game" means they will go to more effort and prioritize your health over medical expenses that must be paid for by insurance companies.
RE: Proof of NO brain is exposed by using the 'having skin in the game' as a valid argument.