I think it depends how one defines greed. Right now there is a big movement in the US, especially among some Christian groups, to encourage monetary greed as sanctioned by Jesus and what makes America great. That greed is part of the fundamentals of democracy and capitalism.
I do wish they would change the definition of greedy. It is used to explain any type of behavior where someone selfishly focuses on their own gain. But, I think there is healthy greed, and greed that goes over the line. I prefer healthy greed to have a new word.
I never could be terribly greedy. I have my limit where I start to feel like I have enough, and I want others to be able to have also. But, I do like good value for money I spend, some might perceive my being prudent with spending money as cheap and greedy? Not sure.
The greed satisfies some sort of ego thing for certain people I guess. They feel like big man on campus. Wealth does give you power and independence, some people just never feel like they have enough of it.
Some people are greedy about everything, not just money, and I assume it goes back to their upbringing. Maybe they were very competitive with siblings or friends? Maybe they feel emotionally empty, and material things fill their soul when nothing else does? Although, I would even argue people can be greedy about other people’s time, demanding attention, because of their own neediness.
All sorts of reasons I guess.