>GrubHub would argue that their logos are everywhere on these menus and it’s clear that they’re acting as agent
Which is obvious to anyone who can and does read text. It seems to me that CA protects businesses not from impostors, but from illiterate who cannot differentiate delivery from production and they just rush to review on completely separate review platforms (it is wrong even if delivery contracted with production beforehand, imagine an angry customer reviewing bricks from a brick factory because a reseller brought them half a trailer of bricks broken in half). I bet that when you call a number, they even introduce as “grubhub support”, not as a restaurant. Not only this law treats a symptom rather than a disease, it also allows established monopolies who first used this “loophole” to retain their status in the future.
As of the problem as a whole - restaurants with their own delivery usually have a much worse service than aggregators’. Claims that “they just take our markup” is nonsense, because in practice people do value predictability and ratings of separare delivery services, while they cannot really stick a lever into many different companies that produce nice food but their delivery guys simply suck “because it’s small place and they have to meet ends”. The alternative is not their own delivery, the real alternative is to shutdown. Pandemic changed markets and fault tolerances drastically and those who ignore these facts are unlikely to bloom in it anyway.