I think the real thing here is, "Better safe than sorry". It's fine to use things like HALT testing initially to say, "this drug should be effective for 8 years" so that folks can get it to market before 8 years have passed.

But if, in reality, that drug only lasts for a strong 5 years, after which time it loses effectiveness, especially in high humidity or with high UV exposure. We could catch this with real-time tests and adjust accordingly - before it actually affects the general public's health.