I think the concept of greed has religious roots where it's a struggle to recognize sufficiency and be satisfied by it. Baked into all humans, an urge to have more than whatever we have at a given time, which mixes with one other flaw, our ability to lie to ourselves, and the result is we can have a hard time appreciating what we have. Of all the ideas from religion, this one's seemed the most well-established and proven in real world observation from my anecdotal experience. It seems as though if there is a conscious creator of the universe, they've balanced this to be challenging for us and imbued magical meaning into the challenge.