So please enlighten me instead of just slamming what seems a fairly obvious point without adding anything of actual substance to the discussion. Because from the perspective of an actual patient it seems rather silly that a nurse can't take a blood test, and a paediatrician-in-training can't study with a family doctor or another paediatrician in a private practice. And it seems absurd that extensive state funding is now accepted as necessary simply to certify someone to oversee tasks like prescribing antibiotics, or signing-off on STD tests, or allowing patients to get blood test results.
No-one is suggesting that neurosurgery should be done by people without specialized training (I would actually think that "residency" is a poor way of measuring competence in that field as well, fwiw). And by reducing the complaints to this rather silly level all you are really suggesting you have no practical answer to the question of why "residency" is a reasonable bottleneck blocking the certification of doctors and keeping the costs of general medical care far above what is actually needed to deliver the vast majority of it that doesn't involve cutting into people's brains.
EDIT: I love the downvotes people, but you would be better off answering the question since I have karma to burn and enough experience with the US medical system to know that "residency" hasn't been necessary for almost any of the medical care I have received.