Re: Box office, ESB never lived up to the original Star Wars. Just looking at original runs (not rereleases), ANH did $307M domestic (that’s $1.3B adjusted for inflation), Empire did $209M ($704M), and RotJ did $252M ($723M).
https://www.google.ca/amp/s/ew.com/movies/star-wars-movies-box-office-comparison/amp/
ESB was a more mature film that didn’t match the runaway success of 1977, and the brighter RotJ didn’t so much better (apples to apples). Did Empire “damage the Star Wars brand” value though? Hardly. For most of its 40 years it’s been critically regarded as
the best Star Wars film. Two new trilogies since, and each have started off strong with box office excitement that tapered off in lower, similar performances for the 2nd and 3rd acts. If a new trilogy ever did come, who would be surprised to see that happen again?
30-40 years from now we’ll still be talking about our favorite Star Wars films, and how they did financially (“only” making Disney a billion dollars? The horror!) will be merely trivia.