With the increasing regulatory burden and outright outlawing of animal models in scientific research biological studies are moving to new far-abstracted models that are much cheaper, easier, higher N, and counterintuitively, way, way less predictive of the actual results in human bodies. Testing 1,000,000 compounds in single cell tests (or just chemical binding assays) in a micro-well array has less predictive power and useful outcome than testing 10 compounds in monkeys. At least when it comes to figuring out which things will work in human disease. The giant massively abstracted studies also generate false positives that waste time. But they do generate publications so they're selected for at the funding level.
That's part of the reason biological research was so much more productive per $ input last century.