Does the AMA want that or is that the purview of state medical boards? AMA doesn't set practice laws. The people who lobby against new grad MDs having the same practice rights as NPs/PAs are NPs and PAs (more NPs). NPs lobby against assistant-physician laws because why would you want someone who has had 500 hours of clinical shadowing while completing their part-time online, direct-entry, 100% acceptance, diploma-mill school (NP) vs. a new-grad physician who's had 2 years of physiology, anatomy, and pharmacology and 2 years with 5000 clinical hours where there's actually an expectation that you contribute treatment plans and care to the team. The fact that the AMA has been asleep at the wheel and unable to stop NPs from getting independent practice in 20+ states show that they don't have any real influence on who practices where.

The AMA also argues against prescription rights for other health professionals like pharmacists (who often have much more in-depth education on drugs)

What do you have to do before you prescribe a drug? Make a diagnosis, which is what is taught in medical school and not in pharmacy school. Pharmacists are frequently embedded in care teams in hospitals and primary care clinics where they make medication recommendations and know how to get drugs approved by insurance companies (sad that this has to happen...).

It's totally possible to have one party diagnose and another prescribe.

you are correct, doctors should stay in their lane and diagnose and leave treatments to others