It is often more ethical to design a study where you compare efficacy to a known efficacious solution and see if there's a benefit, because you don't need an untreated group. Especially for dangerous pathogens. It's also normally done for combination treatments where comparing to baseline is pointless, you want to see if two treatments together is more effective than one. I have not figured out the ringwing obsession with double blind placebo trials, I can only figure it is because that's what they go over first in elementary school science for the scientific method. It is like making the cabinet installer learn forestry and milling before learning how to install high end cabinets, then starting over with plywood production forestry and lamination techniques before installing mid grade cabinets. It's a bunch of extra expense, risk, and work for no tangible benefit. The administration is also putting pressure on animal models, which is the ethical way to do placebo studies, the whole MAHA approach to infectious disease is fraught.