You seem to forget that these things were born out of a need anyways. There’s nothing stopping people from doing what they need to do to fulfill their community’s needs.

I actually grew up in a pretty remote village and back then it was devoid of infrastructure, so we did pretty much what you mentioned above. Burnt the garbage in the backyard, dug trenches for drainages, built outhouses (basically just a hole in the ground, but with roof and door), dug wells for water source, etc. But the village is small and everyone know each other, and thus very willing to help each other. However, I’m having a hard time imagining similar stuff would work in a high density modern city. The sheer complexity of plumbing that service a high rise apartment can’t be maintained by some random dude without appropriate training for example.