If interest is waning that’s not inherently the fault of the franchise itself. There’s a lot more stuff competing for eyeballs these days, and not just superhero movies. I feel like the first Guardians Of The Galaxy movie actually stole a little bit of thunder from Star Wars as we hadn’t had a honest to goodness space opera flick in several years at that point.
I agree multiple factors come into play, and competition is a pretty big one, but at the same time the momentum created by TFA and RO seems to have been lost, and it can’t be denied there’s a lot of turmoil in the fanbase. There’s been a lot of debate on whether the classic characters have been effectively used in the ST with 2 out of the big 3 being killed before the end of the second movie. How much of a factor have the classic characters, and the actors portraying them been in the success of Disney’s earliest releases, and how is their absence going to affect future interest in the franchise? What is Star Wars without Luke, Han, Leia, Chewie, Lando, R2-D2, C-3PO, Obi-Wan Kenobi, Yoda, and Darth Vader? The message of the ST thusfar has been clear (and rumors have been circling around as to why): out with the old, in with the new. Was that a good choice on the part of Disney? Galaxy’s Edge is a great example, which focusses completely on the ST era, and seems to be heading towards a failure.