The lawsuit seems to focus on the history of how that happened a bit. Namely Google seems to have initially tried to sell this API to restaurants directly. Hence the brazen trademark infringement and restaurant impersonation, it was intended to operate with the authorization of the restaurants directly. Only when that failed did they move on to third party distributors that didn't have any right to the trademarks, without changing the now deceptive interface.
> I don't think Google even takes a cut!
The lawsuit is a bit unclear on that (through information and belief) but also cites alternative revenue streams through ads and pushing more people onto its own payment platform.