Sounds quite measurable actually, so forgive me if I don't take your word for it. A promising new drug with a hidden side effect that is, for example, only observable 10-20 years later, could conceivably kill far more people than all the good drugs waiting to be approved could save.

I agree things could be sped up for things that treat terminal conditions, but that's not the majority of pharmaceuticals and even there, the situation isn't that simple.