I lived in very rural north Idaho for a bit, and used an outhouse. I also had friends who had outhouses. "Running water" was when we tipped the water jug to the side. Toilets were common if one had an actual house, but there are a lot of people who live waaaayy back in the woods who don't have modern conveniences...like toilets, telephone, electricity. A common dwelling among the mountain-folk was a 30 year-old camper trailer with a one-room cabin attached.
I'm not sure if they chose that lifestyle, or if it is extreme poverty. (For us, we initially chose it, but once the romance of "roughing it" wore off...well, "north Idaho" is synonymous with "extreme poverty", and we were trapped there for a couple years).