[manholio]

It is completely irrelevant if Google takes a cut or not. Google uses the restaurant's brand name to enable one of their delivery partners to undercut the restaurant's own delivery system.

The nature of the partnership between Google and the delivery firm is not directly relevant to the restaurant's loss of revenue. They could be building a future business, they could be compensated in an indirect fashion (ex. those who pay more to AdSense get a preferential treatment) etc.