In general clinical trials are important and necessary. In any other area, one has to show that the “things” (in this case, medicines/treatments) work as expected – clinical trials serve such a purpose.
However, underlying scientific concepts and practices in the medicines area are extremely poor; hence “clinical trials” practices face credibility issues. For example, developing products (tablet/capsule) clinical trials (bioequivalence test – regulatory requirement) are conducted, lacking clinical relevance and usefulness. Therefore, it could be argued that such tests indeed expose subjects, often healthy human volunteers, needlessly to potent chemicals in the name of medicines development. (link)
Similarly, relating to the Coronavirus pandemic, there appears to be a rush towards the development of medicines/vaccines. It may be argued that as the underlying analytical science is not well-established to monitor the virus and/or its “disease,” it would be challenging to conduct appropriate and validated “clinical trials” (link)
In short, running clinical trials is a good idea. However, conducting appropriate and useful clinical trials remains challenging; that is where the confusion is.