Most times, we just order directly from the restaurant if they still deliver. Just Lysol the outside packaging and good to go.
I don’t think they are “doing it” so much as operating a subsidiary that provides this service/device to restaurants. It doesn’t make logistical sense that GrubHub drivers have to go to pick up from 2 locations to deliver burgers and a salad. My guess is they want to upsell services to their restaurant clients who would then provide you a burger and a salad.