HearthyMeatballs. Everyone is trying their best, but the whole set up needs more thought.
Not enough food is being loaded. 3 ploughman sandwhiches for a 321 going to Cyrpus. Really now? Yet 10 bacon sandwiches on an AMS where they have no time to cook them anyway. Makes complete sense.
Easyjet have more passengers but they take cash which actually is pretty quick to transact. BA have these ipads that quite simply do not work as quickly as planned. Took a friend of mine 20 minutes to pay on a 50 minute flight. So on the short flights not everyone gets served, on the long flights they run out anyway. Sure some staff may want it to fail, but they are not going to risk their jobs over it, get real.
On the subject of water, it is deemed safe to drink, and at many overseas airports the water is not uplifted as it doesn't meet accepted standards. This can lead to aircraft running out of water on certain routes. So the last thing you want to start doing is handing it out to passengers to drink. Furthermore, on certain aircraft it is not possible to despense cold water from the galley, only hot water for making drinks.