I have been working in a pioneer cemetery. The first three burials c 1823 were children....all from the same family. I know they lived near a mill site.
As cities grew, these problems grew...and we began to try to control the sewage and provide potable water.
Be thankful for these resources.
Weren't boiling water, washing vegetables in boiled water or avoiding raw food (veggies or steak tartare) sufficient to deal with the problem?
Yes, water and sewer is what make the cities possible, they have always been the problem.
Get millions of people disconnecting, and problems and deaths, and illness would start spreading.
It is like using grey water, it is great for some and I used to encourage it a lot, it should be done by those who do it right, but I have seen some pretty filthy ways of people dumping dirty water in their yards, it can get pretty bad after years of simply running an open pipe out there. Some people just do things with no thought or knowledge, just because it is easy, like for instance just letting a broken pipe empty on the ground and calling it, their grey water usage.