I'll try, but my 3 previous GPs, who were all better than my current one, are no longer in-network. Presumably the insurance doesn't pay well enough to keep the better doctors. It's a substantial amount of paperwork (both with the insurance and the new GP) with no guarantee things will be better.
For many people it is. They cannot see another doctor if they want to continue doing things like eating food. If they're lucky enough to be insured at all.