It's an excellent point. Learning is not the same as science, and we need randomized trials to actually be sure of anything.
Unfortunately, in the middle of a pandemic, that's not going to happen with enough speed to prevent a lot of people dying.
The perfect can be the enemy of the good enough. We don't have to guess or learn about the mass of an electron; that's been well-established through great lab work. But not all decisions are like that. Many times the hardest decisions are those you make with incomplete and contradictory information ... and not making a decision is, in effect, making a decision. This is one of the things that's so interesting here. If it were simple yes/no, what's science and what's speculation, there wouldn't be much interesting learning or decision-making happening.