Pretty much everyone else isn't.
People could grow their own food, eat straight nutrients if we had to.
Without plumbing you have no waste drain and no flowing water. I imagine you forgot about the irrigation aspect of farming.
Discovering plumbing, waste disposal and aqueducts[1] allow society to live in close quarters.
I had this realization over last one year, after 17 years of professional life.
Most of my work these days involves plumbing together right libraries and data pipelines to automate business processes. Sometimes I need to fix an existing plumbing to plug a leak here and there.
Now my Twitter handle says Plumber
FWIW I like both terms. I just wouldn't use them interchangeably. :)
But not residential. That's all pretty standardized.
Think industrial, or a nuclear power plant. Or a spacecraft. Something where everything had to be custom designed.