Basically, it takes two movies for Anakin to get where Luke is at the end of ANH, and that is heavily problematic to the structure of the trilogy. I enjoy ROTS, but there was just too much material crammed in as Lucas basically procrastinated the most important parts of the main character’s journey.
That hits the nail on the head. Revenge of the Sith had to cram in every last plot point to bridge the gap between the prequels and originals. Those elements being the victims of “procrastination” in the films is probably the best I’ve heard it described.