The core of FDA regulatory power covers issues like how much evidence is enough to declare a drug fit for the public, how bad can the side effects be for its intended purpose, how to deal with ethical questions regarding everything from patient welfare to clinical trials, and regulating all of the infrastructure necessary to carry out the former activities. None of that disappears just because you nationalize the industry because it's all infrastructure necessary to innovate in medicine without causing significant collateral damage. The FDA is particularly heavy handed due to that fundamental antagonism but all that work still needs to be done and it's really complex. A lot of it is done by contract research organizations, some of them in the billions of revenue themselves, and nationalizing the pharmaceutical industry would make their work even more important.