The trick is to take the billionaires money and put it to use producing things, not consuming things. There are tons of ways to do this such as investing in education, small business loans, scientific grants, and big infrastructure projects. Absolutely! China has made great strides in tying production to actual needs.

Another solution is to increase immigration to make up the production imbalance. Good luck getting that through todays political climate, but most economists would agree it would help alleviate the problem OP referenced.

A healthy immigrant policy can compliment a healthy production policy.