Been thinking about this one a lot lately. The way the lines are laid out - some stretching for miles in perfectly straight formations - it doesn't really make sense as a "lived in" landscape does it. More like a ceremonial space that people came to, used, then left.
There's decent evidence the Nazca had settlement sites away from the plateau itself, so my current thinking is the lines were more like a pilgrimage destination. Maybe tied to water worship given how dry that region is. You make a long journey to walk a giant hummingbird into existence and pray for rain, that sort of thing.
What I cant work out is whether different groups had "ownership" of specific geoglyphs or if it was more communal. Has anyone read anything on the social organisation side of it? That bit seems underexplored compared to all the "were they runways" nonsense that still does the rounds.