Scientists spend more time empire building and attending endless team meetings instead of conducting actual scientific research. Within R&D, around 90% of the PhD level scientists never actually do any real lab work. And there are A LOT of PhD level scientists.

This is because PhD level scientists are rewarded more for middle-management style team leading achievements. Therefore, there are no scientists leading from the lab bench, where the real work is done.

In addition, scientists end up chasing bad drug candidates long after they have discovered troubling properties of these compounds. This is because the reward system is set up to reward PhD's for leading teams, not leading science. In some cases, scientists are punished for pulling the plug on bad drug targets, even though it was the right call. They end up with bad annual reviews or they are passed over for other team leading opportunities.

This is why so many drugs fail once they get to Phase I/II/III clinical trials, because they were terrible drug candidates to begin with.