Benefits to the Assistant Physician (AP) legislation:
Benefit #1 - Creates competition with encroaching mid-level "providers"
Right now with the "Doctor" of Nursing Practice, the effort has been to expand scope-of-practice to that of board-certified physicians. In other words, the nursing lobby is competing directly with the AMA over the exact same role.
By creating a new brand of mid-level, it gives the nursing lobby a brand new enemy, and one with which they will directly compete for jobs. Do you think the MBAs and the multi-millionaire schmucks who run the hospital give a damn who it is that is providing healthcare so long as the patients are happy to receive and pay for it? An AP will be no different to them than an NP or a PA. Just another piece of labor they will try to pay as little as possible for.
The amazing thing about this strategy is that it won't hurt board-certified physicians one bit, since the Assistant Physicians will be under the direct control of the board of medicine and require supervision by law (same as PAs). It will exclusively hurt those who require supervision of a board-certified physician.
If you don't think this strategy will send the AANP into total panic mode, just look at what happened when the American Society of Anesthesiologists tried to get Anesthesia Assistants legalized in every state. The CRNAs went into complete meltdown across the country, since it was a direct threat to their economic interests. It also hurt the CRNA scope of practice expansion push by virtue of creating an entirely new battlefront which their lobbyists had to fight. For a while it no longer became about "CRNA vs. Anesthesiologist" (or "MDA"), but "CRNA vs. new mid-level anesthesia providers."
As more evidence - did you ever notice how Nurse Practitioners almost uniformly oppose scope-of-practice expansion for PAs?
Lastly, think about this for a second. The AANP is going full-time at this narrative about board-certified physicians/attendings being no better than NPs. But their strategy so far as been to use severely flawed observation studies as evidence of this equivalence. Their argument has never been to compare their own training with that of attendings. In fact, they are very careful to avoid going down that road because it is such a huge discrepancy that even the average idiot on the street wouldn't buy it.
By creating the "Assistant Physician" role, it forces the new narrative across that Non-residency trained physicians are just as qualified as newly graduated NPs. The great thing is that the AANP can't really say it isn't true without attacking medical education itself. They can't really say, "Well those doctors didn't do a residency so they're not qualified" since obviously they don't do residencies.
Benefit #2 - Helps delegitimize propaganda efforts aimed at making the public believe all "providers" are equal
Another benefit is the press coverage itself. Stories on the issue will by necessity educate the ignorant public of the vast differences between board-certified physicians and other healthcare "providers." The "Doctor" of Nursing Practice degree was created in large part to confuse people about what the term "doctor" means in a health care setting. But if stories like this start appearing around the country, why that could be very bad for the so-called Doctor of Nursing Practice. Might be that the average schmuck starts asking what kind of doctor they're actually seeing, what with all them news articles about undertrained doctors being allowed to treat folk.
Benefit #3 - Upward pressure on resident salaries/benefits
People are falsely thinking the true benefit of the law will be that those who fail to match get a job. That isn't true. The benefit will be that those who choose not to match get a job.
The people who (for whatever reason) don't want to work 80+ hours per week at the hourly equivalent of minimum wage decide instead to just function as a mid-level for 2-3x the salary/benefits (in other words, what NPs/PAs make right after they graduate).
This will create some small measure of competition between the Match/ACGME/AMA/Anti-Trust-exempt monopoly system and the "Assistant Physician" route. Right now, resident salaries are price-fixed. There is no financial incentive for programs to offer better benefits or salary. There is no incentive for them to provide affordable health insurance. But offering a financially viable alternative to residency will pressure the Monopoly System to offer more, even if it is not much more.