I think it's a fallacy to say that pharmaceutical financial interests are not aligned with actually effectively curing diseases.

First, when they cure a disease we don't sudenly become immortal, it improves our life quality and expectancy and new diseases become more prevalent at a later stage, so they don't lose their jobs.

Second, even if slowing down research could effectively allow them to benefit longer from existing cures, generally you have competitors and inertia tends to not work well in adversarial conditions.