There was a thread awhile back on the “greatest inventions”. It was way deep into the comments - but some Freeper said his grandmother told him “running water”.
I think the Romans would agree. And I imagine without running water, many of the folks that invented other things would have died of disease before they could ever get around to inventing the other stuff. Or - too busy hauling water from the pond.
Heh, yeah, because of where and when I grew up, I just barely missed the "convenience" of hand-pumped wells -- which had been a huge improvement. Homebrew was a necessity for the frontier, and for pre-Age of Sail Europe both rural and urban. The hops still grow here.