I almost fly CX873/CX872 exclusively. I do not know much about the other flights. FAs do make water (and sometimes OJ) passes from time-to-time. I may be wrong, but I think they do pass bottled water to PEY passengers too. There are snacks and fruit in the Y gallery. They are usually there until 2-3 hours before landing. So you can ring the call button or just walk to the gallery to get snacks (or cup noodles). I am surprised your experience is very different.