To ignore _all_ clinical studies because “nothing useful comes out of them” seems extreme. Yes, there are poorly run studies, and conclusions can be inappropriately drawn from studies (ex: when a study wasn’t meant to answer certain questions).

However, well-run randomized control trials (RCTs) in medicine absolutely exist and can be a very strong form of evidence when interpreted correctly. This is especially true in comparison to other disciplines (economics, etc.) where such RCT trials are impossible and researchers wish that they a research tool as valuable as an RCT.