It depends on the specifics of the experiment. Throughout the 20th century, the people most keen on unethical medical experiments seemed the least able to design useful experiments. Sometimes people claim that we learned lots from the horrific medical experiments taking place at Nazi concentration camps or Japanese facilities under Unit 731, but at best, it’s stuff like how long does it take a horribly malnourished person to die if their organs are removed without anaesthesia or how long does it take a horribly malnourished person who’s been beaten for weeks to freeze to death, which aren’t much use.
It depends on the specifics of the experiment. Throughout the 20th century, the people most keen on unethical medical experiments seemed the least able to design useful experiments. Sometimes people claim that we learned lots from the horrific medical experiments taking place at Nazi concentration camps or Japanese facilities under Unit 731, but at best, it’s stuff like how long does it take a horribly malnourished person to die if their organs are removed without anaesthesia or how long does it take a horribly malnourished person who’s been beaten for weeks to freeze to death, which aren’t much use.