Need help understanding use case diagram

So there's this use case diagram I'm referring to which has me confused. See below link. What I don't understand is that in this particular example, how come there isn't a connection for the "cook food" use case to the waiter? Since he has to receive the cooked food in order to serve it? Then again how come the "serve food" use case doesn't have a line connecting it to the client? Since the client has to receive the served food in order to eat the food? Finally how come the "eat food" use case isn't connected to the waiter? Since the waiter has to collect the eaten food (empty plates)/receive notice that the client is done eating before he can facilitate payment? I'm super confused about this one, if anyone can offer any help I would really appreciate it.

Link: https://en.wikipedia.org/wiki/Use_case_diagram#/media/File:Use_case_restaurant_model.svg