In the science world, not one defined by getting a graduate degree dealing with "psychology, language, and social and cultural issues", mice are not little people. That is why animal models and epidemiology are in the "exploratory" section. If scientists see something that looks like more than correlation, something that may have a plausible biological mechanism involved, they will tackle it.
The number of drugs or medical devices that can go to human clinical trials without an animal model is zero. For good reason. Computer simulations are not magic, despite what PETA now claims. Instead, animal models are necessary to exclude a positive or negative effect. If a product can survive animal studies, then it is considered for human clinical trials. Animal models can never prove something is harmful to humans, nor can they prove a benefit. But they are vital to the process.
PETA either doesn't understand chemistry and biology or deny it in order to weaponize reality for their agenda. They note that 95% of drugs fail in human clinical trials and 90% of basic research never leads to treatments, vaccines, or cures.
It's likely even higher than that. But in animal models, cancer has been cured thousands of times. In computer simulations, even more. That they then fail in human trials is why discovery is so expensive. If animal models were eliminated, new drugs, including vaccines, would become extinct. No one would take the risk of going from computer simulation or in vitro models to human trials.
Dr. Collins will be difficult to replace, but the worst thing for American science would be to replace him with someone who would make NIH funding a football kicked around by activists.