Been wondering about this for ages. My gut says they probably didn't live right on the lines themselves, more like the lines were a kind of sacred space you'd visit rather than hang around on. Like a church - you don't live in it do you.
From what I've read the settlements were mostly in the valleys where the water was, which makes sense in a desert. So they'd travel out to the plateau for whatever rituals or ceremonies they had going on.
What I find interesting is whether the lines were actually processional routes, like people physically walking them as part of something religious. That would explain the scale a bit better to me.
Anyone here dug into the archaeology side of this? I'm more into earth mysteries than proper archaeology so I might be missing something obvious. Would love to know if theres actual settlement evidence close to the lines or not.