Okay, so the lobbying will move to doctors. And while FDA lobbying is public, good luck guessing who gave a kick back to your doc. A single regulatory body is easier to monitor than a hundred of thousands of them. Doctors getting kickbacks is already a thing so I can't imagine how it wouldn't get worst if they had the power to prescribe anything they want, not just FDA approved meds
It's worth mentioning that MDs and pharmacists in the US both have approximately 4 years of schooling (among other things) in addition to their bachelors.