This article summarizes the need for physicians not only in the US, but all across the globe. The global shortage is expected to be 20% lower than what is needed. 45 countries in total are expected to have a shortage of physicians, and Africa is expected to be hit hardest. The source also compares what areas need the most physicians for treatment based on the number of people with diseases and health issues. It is suggested that countries with a shortage must expand their medical training programs in order to meet the need.
This source helps me to further learn than this shortage is expected around the world. It also shows how much bigger the problem is.
I still need to find what would happen without physicians if possible.