Why not open more medical schools? And eliminate the matching system? If you want to be an ____-ologist, here is the list of requirements. Meet the requirements and you are the ___ologist. Not whether or not a practice group likes you, or your parents knew which colleague to talk to. Don't allow the supply of MDs to be constrained.
The bigger restriction is number of residency positions which has been limited by government funding constraints. Also you need sufficient skilled doctors to train these residents. There is also the issue of physician burnout and preferences of doctors to be specialist vs being in primary care. So what often happens is foreign medical grads apply for these kind of roles. Also foreign medical doctors have a couple of requirements to work in the US. Get their foreign degree reviews to meet requirements, pass the US medical exams and finally they have to redo their residency even if they have significant experience. Some of this is largely controlled at the state level. Some states are considering loosening the residency part to a shorter period for primary care position for foreign doctors that are willing to work in underserved areas. I know California is also reducing restrictions on foreign dentists.