The response is simple, rich people buy more assets and poor people buys more liabilities. When rich men makes purchases of expensive things, most times they've ascertained that it has possibility of giving them returns either directly or indirectly or even both, but a poor person would buy an expensive material just to look rich.
A rich person plans his expenses and most times save up money separately for an expenses and ends up buying from a fellow rich person and the money circulates within them but a poor person takes money out of his savings to purchase an item from the rich, thereby adding more funds to that already circulating among the rich.
Yeah, this is basically how the cycle keeps looping.
Rich people think in assets first. When they buy expensive stuff, there’s usually a reason behind it appreciation, cash flow, tax angle, connections, or long term leverage. Even luxury purchases are often calculated or come after the asset base is solid.