7 and 8 do not link together. The characters from 7 are not the characters from 8, because both directors had their own interpretations. When people defend 8, they are defending their love of the movie and their parasocial love of Rian, not its cohesiveness in the trilogy or how well it meshes with the other 2 films.
Rey was someone in TFA, Rian decided she was “no one” and then JJ decided she was someone again. There is no way that Rian thought she was a secret Palpatine when he made 8.
Kylo was Vader obsessed in TFA, 4 minutes later in TLJ (in universe time) he isn’t, and ROS he is back to Vader obsessed.
Snoke was a mysterious new emperor in TFA, TLJ said he was a joke nobody, ROS then said he was back to being a mysterious new emperor (clone thing). This is on record that JJ did not expect Rian to kill off the big bad unceremoniously.
This is not saying JJ’s writing is good. This is saying that the two different directors clearly had different visions of what they wanted the characters to be.
Listen, I fail to understand this. How was Rey someone in TFA? The only thing TFA says is that she’s someone destined to do great things - but that doesn’t mean she’s a big character’s daughter or granddaughter or whatever. Sure, Abrams resorts to cheap tricks (which is all he knows) like cutting away from Maz and Han discussing who she is and setting up an empty mystery box - something Star Wars has never been known for (it’s always been straightforward and makes its characters and plot interesting without the need for such flat techniques) - but you can’t say for sure she’s someone just because Abrams wants you to chew on who she is. Her being nobody is a more interesting way out thematically and story-wise as well. New blood, dammit, it’s a big galaxy.
Snoke - as, the way I see it, an insert of Rian - tells Kylo he’s a failure as a “Vader wannabe” and tells him to “take that ridiculous mask off”. Kylo then sets off to find an identity of his own after spectacularly failing in being a worhy successor to Vader in TFA. That’s an interesting character choice which allowed the writers more freedom and a potentially more compelling character arc for him in IX, since Kylo became completely independent from anything of the past in TLJ, something that makes sense. His 180° wasn’t out of nowhere, it was carefully constructed.
TLJ never said Snoke was a “joke nobody”. Sure it may have told the audiennce that setting mystery boxes like that is a stupid thing to do - because it is - but the characters all know what’s up. We don’t because Abrams chose to set his movie 30 years in the future and do little to no worldbuilding.
The thing here is: TLJ needed, to please everyone, to be a 4h picture structured like The Godfather Part II. Abrams didn’t set up a single thing in this post-ROTJ universe. During the making of TFA he was enjoying this fantasy of being 1976 George Lucas and threw us in the middle of a story, but he demonstrates laughable writing skills when compared to Lucas in terms of how he builds his world. TFA being Episode VII also means he has to do a lot more explaining here - he doesn’t have the freedom Lucas had, he’s not creating a universe from scratch - so he needs to set up the political state of the galaxy in order for us to understand why anything the characters do matters, and he needs to set up his characters, both old and new, their motivations, etc - something he arguably did for most of them, but, as your complaint about Snoke shows us - clearly not all of them.
Rian had to answer all of TFA’s questions - both about the past and the present - while also being a movie with its own voice - and it succeeded as much as it could. Rian even uses flashbacks, something no Star Wars would ever dream of doing, because of the shit hand Abrams dealt him. But all the characters in TLJ are an absolute continuation from those of TFA, to a tee. A direct sequel if I’ve ever seen one, and a good one at that. I’m convinced TLJ is the best movie we could possibly have gotten given TFA.
TROS I’d rather not acknowledge, but if I have to, I’ll just physically cringe for a second in the corner.