Ask HN: Have we made a mistake by not conducting Covid tests on humans?

There is still so much we don't know about COVID that we are simply discerning through statistics instead of hard science. At what point are people contagious? How much virus do we need for someone to get infected by COVID? Why do some people get severe symptoms and others get no symptoms at all? Is there a genetic link? Why do naive immune systems of kids defeat COVID so easily compared to older immune systems?

It seems like if we had controlled environments where we could infect humans and then watch the progression, we could have saved literally millions of lives.

And there are hundreds of thousands of people if not millions who would volunteer for these experiments around the world. We could give them a stipend, maybe $10,000 or $100,000 and direct access to monoclonal antibodies, paxlovid, and the best medical care available. I myself would volunteer under these conditions.

But I think there's probably an ethical reason why we haven't done this. Surely having controlled experiments on volunteers would help us figure out how to stop this disease much, much sooner? Especially given how low the death rate was?

Is there any reason besides ethical why we wouldn't want to test on humans to get a better understanding of COVID?