Someone with background in finances will tell you that it's a lack of money, someone with a degree in economics will say it's a lack of resources to satisfy basic needs, I say it's lack of knowledge, skill and opportunities.
You don't need money, but you either need skill, so that you can steal or persuade other people to give you what you need, or you need an opportunity.
I've earned a lot of money through an opportunity because someone told me to research bitcoin and I did, got hooked and it became the best investment of my life. I know people who are wealthy because, for instance, they married into a wealthy family - which again is skill and opportunity combined.