Well Zeus certainly travelled a lot to get all those people pregnant lmao.
On another note, it's a very minor detail but after your talk with the old man you exit the cafeteria and there is only a single person in the station. We don't get any details about this person other than he smokes, Jean (Hermes) is also shown to smoke when meeting Luke. He also talks about the "old man" often. Not that it couldn't be the case, but I can pretty confidently say the old man is not Hermes.
I think the whole idea at this point is that due to the lack of worship the gods are degrading slowly, some faster than others, but inevitably so. I think the idea is that Zeus is pretty out of it, and by chapter 18 Hermes is also a bit depented. The only god who probably won't have such issues is Hades, as we're told undeworld gods tend to have a lot of worshippers in their realms.