Mythology and some meta narrative celebrating the power of mythology is not the same thing.
It can be, though. A blend of the two can be achieved. A metatextual celebration of mythology within a mythology doesn’t disqualify its status AS mythology, and it further doesn’t disqualify the storytelling using that as its engine from being good, either. The Princess Bride is a great example of this.
A lot of your arguments seem focused primarily on that impulse towards disqualification, specifically of the film’s storytelling conceits as not being “Star Wars” in and of itself. Which is limiting, to me. Those limits weren’t applied to Empire, thankfully, and the film that came out of that willingness to experiment and metatextually comment on what came before was all the richer for it. A lot of my favorite things in Star Wars are things that weren’t really “Star Wars” until they were introduced to it.
Some people have a really hard time processing these films AS films in and of themselves, and can’t help but looking at them solely through the perspective of their place in the larger saga. Not that it’s an invalid way to process the movies at all, I’m not saying that. But it also means that interfacing with what these movies are doing AS movies becomes a lot harder when they’re not pre-canonized for analysis and consumption. When something as adventurous and rule-breaking as Empire is already decades old and fully accepted for what it is before you ever clap eyes on it, a lot of the arguments that could be applied as equally as they are to Last Jedi or Force Awakens simply don’t get applied, or are only applied as an academic concern at best, a fun “what if” that is almost beside the point.
Granted, it’s almost impossible not to take into account the movie’s place in a larger series, but I think it’s also unfair to act like movies that safely color within the lines of what “Star Wars IS” are inherently better as cinema than the ones that don’t. Not only are those “rules” often arbitrary and more in the eye of the beholder than in the eye of the storytellers in question, but adherence to those rules aren’t necessarily any sort of real roadmap to successful storytelling.
As much as I dislike Attack of the Clones as cinema, and as storytelling, I wouldn’t consider disqualifying any individual aspect (or the film as a whole) as Star Wars simply because it’s a bad movie. And if I can allow that Star Wars by the numbers can lead to something being a massive turd, then I have to allow for the idea that Star Wars outside the box can be brilliant, if not necessarily adherent to traditional ideas of what “Star Wars IS.” Essentially - that rigidity stunts potential, and can stunt appreciation, and if primary complaints about the Last Jedi tend to center on it’s decision to not maintain that percieved rigidity, and doesn’t take into account how well those elements were actually EXECUTED… those complaints read to me as self-minimizing. Because what’s more important to me in a movie isn’t necessarily what’s being done, but why it’s being done, and how it was executed.
In the case of the Last Jedi, I have a hard time finding fault with why things are happening in that movie and how they’re being pulled off. The history of the series its a part of serves as a good contrast point, but I also don’t believe it NEEDS to be SO beholden to that history. Which is, itself, one of the lessons the film puts forth.