Restaurant Delivery Services

Of course it depends (corporations which tell their employees to break the law, e.g. run red lights, can have the corporate veil pierced and the ownership could even be liable). Delivery people may be employees, independent contractors, day laborers... hard to say.

Anyone with half a brain is suing all three and letting them duke it out when it comes to liability.

Hmm isn't there a Seinfeld episode eerily similar to this?

https://seinfeldlaw.com/2020/10/19/the-virgin-negligence-per-se/

Most of these sorts of delivery people are independent contractors (at least the ones you list) unless they are directly hired by the restaurant - which people like doordash and ubereats are not so in those cases you would sue the individual. They probably do not have much money so you would not recoup much in settlement.