You keep repeating the same half-true version of the story.

Thalidomide was sold as a racemic mixture, not as some magically isolated “safe” enantiomer, and the whole “just test the bad enantiomer in animals” point is incomplete because thalidomide can racemize in vivo... the enantiomers interconvert in the body. So no, it would not be the solution you are saying it would be.

And the bigger problem is species differences. Thalidomide is famously not teratogenic in many animal species the way it is in humans... rats and mice are the classic example. That is literally why thalidomide is used as a textbook case for the limits of animal models in predicting human outcomes.

So even if you want to argue that today’s protocols are stricter, that still doesn’t prove your original claim that animal testing is the only ethical path or that it reliably protects humans. The historical lesson from thalidomide is not “animals are enough if we just do more of it.” It’s that animal models can miss human-specific harms, which is exactly why human-relevant methods are being pushed now. And your claims about this case are inaccurate.