It's nothing like either of those things because both of those things have harms to other people and those harms scale linearly with the amount of consumption. Wasting steak isn't problematic because you run out of cows it's problematic because of the climate impact of raising them.

Saying that saving water is "about respect" or something is idiotic. Saving water is about ensuring there's enough water to go around. This is something you need to do in places where water is scarce and not where it isn't. And if you waste time and energy on saving water you are ultimately making the world poorer.

Obviously I'm simplifying things by talking in absolutes here, but what I said above about "the margin at which it makes sense" gets at the truth of the matter. Installing water-saving taps in Zürich is almost certainly a net harm to the environment.