And indeed the link is even more basic than that. Once you get past what you can spend to maintain a lifestyle, wealth is basically a measure of how much of societies resources you can call in, and to make more of it the better options are to organise people to do useful work.
It isn't a class thing that the rich organise the work. Organising people is approximately what makes a person rich.
If someone is organising large numbers of people and is poor ... that is more than a choice, they'd have to be working quite hard not to be bouyed into wealth. It is easy and natural to leverage followers into riches.