Regulatory caution is a rational response to asymmetric consequences, unfamiliar failure modes, and population-scale decisions — not resistance to new technology.
The two errors are not equal
Approving a harmful drug harms patients who cannot evaluate the evidence. Rejecting a useful drug costs time, and the developer can return with stronger data. Because the errors are unequal, the default leans toward rejection until the case for approval is strong.
Novelty moves risk onto the patient
A new design method has a shorter track record, so its failure modes are less understood. A method that performs well on the cases it was built for may behave unpredictably on a different population or disease. Until that is characterized, the uncertainty counts as real risk.
A regulatory decision applies to everyone who might receive the drug, not to one patient. At that scale, rare but serious harms carry weight even when the average benefit looks favorable.