You're looking at it from the point of view of your existing situation.

Firstly, your roads. I owned a cottage which had a half-mile muddy track to it. I improved the road and it's still there and still in use. OK, so I used a farmers tractor and trailer to take stone to it but before that I filled the ruts with broken bricks.

In times past, without vehicles would you need a metalled road? You'd only need a passable trackway. People out in the back of beyond got together and improved their trackways which over time became roads. Those abroad could do the same if they pulled together.

I presume you have either a cesspit or a septic tank? So how do you reckon people there went on in times past? There were a couple of ways they went on. One way was to have an "outhouse" which was literally a bit of a shed over a hole in the ground. When the "hole" underneath was "full", they simply moved the shed and covered the "hole" with debris removed from the new hole.

A more permanent set up was also an outhouse but that was a permanent structure, purpose-built. Before the building was built, the ground was prepared with a slightly sloping brick floor. The slope led to a door and what happened was after time, the waste gradually made its way down the slope and after a considerable time when it was well-rotted (!!!!!) it was scraped out and "disposed of". Either they simply dug a hole and buried it or they (wait for it) spread it on a fallow field!

I agree that those living "the simple life" are those most likely to survive a major catastrophe as they'd probably have all they needed to carry on life.