I don’t know any researcher that likes sacrificing animals though every single one is painfully aware of the moral weight. They also go out of their way to minimize suffering, for ethical reasons, for selfish reasons, and even to improve the quality of the data. The reason I jumped down the parent's throat is because it reinforces the mistaken idea that scientists are okay with “moderately barbaric” things and indifferent to suffering. We aren’t!

And what’s the alternative to animal research? Computational modeling isn’t there yet and in vitro experiments have pretty stark limitations too. In any case, both would need animal data to determine if they’re correct. Waiting for another Nazi regime[0], as you proposed(!), doesn’t seem like a viable—-or ethical—-option.

[0] Incidentally, I have read that most of that “data” was scientifically useless, not just because of its moral provenance, but also because the stuff that was done was more akin to torture than controlled research.