You ignored the information about the restaurant's popularity, which indicates that the gp took demand for teh chef's services into account.

it starts and ends with raw numbers

No it doesn't. If that were true markets would be reliably self-correcting and market failures would never occur, rent seeking wouldn't be profitable and so on. In reality there are variations in elasticity of demand and supply, regulatory issues, and economic network phenomena like preferential attachment, all of which substantially complicate the picture.