Are those tribes who are still living a secluded life in the forests of Amazon or say even those who are completely isolated like in Indian ocean islands considered poor? They've had everything they need and unless there's no external interference(Humans, Weather events e.g. Tsunami) they're living a successful life.
Also I have serious issues with the term 'Civilization', I don't know how tribes who have been co-existing with nature successfully for thousands of years could be called uncivilized where as we who have set in motion the likely destruction of vast majority of the species on the planet considered civilized?
I feel that mentality is a relic of colonial mindset, There are vast amount of written accounts of colonists calling the indigenous people 'Uncivilized'.