Star Wars and originality feels like a different topic.
Look those original three films are not perfect. Nothing is perfect but as far as movies go they are about as perfect as you get. That's why they are so revered as classics because their appeal has endured for so long. The flaws that fans point out aren't so distracting that they take me out of the story. Maybe it does for some fans the same way the flaws of the ST take me out of that story.
All I'm arguing is that it's easy to take pot shots at the originals to shore up a defense for the new stuff. I just think that's a weak position to take rather than letting the ST stand on its own. The originals have nothing to prove because time has proven them.
The themes and similarities between trilogies may overlap or are refrained like a chord in a song but the execution of those themes was far superior in the originals. If they weren't we wouldn't even be having this discussion.
I think, and this is where nostalgia bias comes into play, that we only accept the flaws of the OT, and in fact time has as well, because well, most of us grew up with them. Back in 1977 through 1983, audiences didn't pick through the OT with a fine toothed comb. There was nothing to compare it to, and no reason to. But because we grew up with the OT, we've accepted its flaws, and are willing to overlook them for the enjoyment of the movies. I remember when the PT first came out, back in 1999. I was 6 years old, and would you believe it, I still liked the OT was better than what I thought was kiddiefied garbage with its yippee-yelling Anakin Skywalker and goofy-ass Jar Jar Binks. I remember we had a Star Wars day in school, and everybody showed up as either Anakin, Queen Amidala, Jar Jar, or Darth Maul... I was the only one who showed up as an OT character: Darth Vader. I later reused that costume for Halloween that October:
But my point is, we're familiar with all the OT and all the flaws therein. That makes them less obvious, and because it's something we love, we're willing to accept them more than something that's new and has flaws.
Well, everything in the OT can actually exist in universe. A base, built through the center of a moon, close enough to a sun to steal all it's power and destroy it - but there's snow on it's surface? It's NOT baked into oblivion? I'd wager no in-universe materials can pass that close to a sun for much more than a handful of minutes. Not live there. Watching the movie it doesn't bug me too much, but it's not plausible in the way it was done. It never occurred to me to be honest until i went looking for a ST thing to nitpick. It only took 15-30 seconds to come up with that though.
And that's nit picking. I'm sure you can find story problems in the OT. Thing is - they aren't glaring. There story problems with the ST that are glaring. Doesn't make the OT innocent, but you're talking jaywalking vs grand theft auto.
And i'm sorry, but while the OT had a good share of figure it out flick by flick - you can't say the ST was 'similar' in that regard. You had a director who dumped a lot of the OT for the new starting point, a second director who threw out most of the last flick, and the final director who tossed most of the second part.
I think the point of contention originates in the definitions of "glaring" and "minor" problems. What one person considers to be a major issue, another person might not. I, personally, think the odd time frame of ESB could potentially be a breaking issue if we begun really really thinking about it. But I choose to overlook it, as many others do, because I love ESB and am willing for forgive the issue.
GL and company at least shot for a cohesive story. They tripped over their own feet hear and there. But they weren't retconning themselves in every flick. Seems like one crew was new to filmmaking but had a good story in mind and the other was good at filmmaking but didn't have a story - at least one they stuck to.
Of course they were! Luke, Leia, and Han were in an obvious love triangle through the first two movies, and then in the third she's Luke's sister. In ANH, Vader killed Luke's father, and then in ESB Vader IS Luke's father. In ESB, The Emperor was a woman in a mask and voiced by Clive Revill. In RotJ, he's played by Ian McDiarmid, and looks and sounds nothing like the ESB Emperor. In ANH there's numerous references to the Empire controlling a chunk of the universe, later we find out it's only one galaxy, which is somehow viewable at the end of ESB. Like I said, Lucas changes his mind every other Tuesday, and retroactively is always "the way I intended it to be." If LFL was still in Lucas' hands, I'd guarantee we'd have seen another SE by now.
The First Order is a Neo-Galactic Empire faction trying to restore the glory of the Empire. Without first 6 films you have no context for what the Empire is. We have no context when Kylo says that he will finish what his grandfather, being Darth Vader, started. So even if you removed all the old characters. The idea that there is no connection to the previous films is a lie.
Not to mention the entire first movie is, generally, about finding Luke Skywalker, the central character of the OT.
But ESB and ROTJ do not stand on their own.
ESB opens with the knowledge that you've seen the previous film. So they don't introduce the characters like we've just met them. It assumes you know about Obi-Wan death and him vanishing. And that you know about Vader, the Force, and the Jedi. And then it ends on cliff hanger, knowing that there is going to be a sequel.
People like to refer to movies like TLJ as "suffering from middle sequel syndrome." When you think about it, most second sequels, when planned as part of a trilogy, suffer from this so called defect. It's not really a defect as much as it is simply part of being the second movie of a planned trilogy. BTTF 2, Dead Man's Chest, Jurassic World: Fallen Kingdom, Empire Strikes Back, etc, are all planned to be a bridging movie that takes our characters from their start, and positions them for their finish. That's the whole point of them. One of the few movies I can think of that doesn't is Temple of Doom, and only because the Indiana Jones movies were planned more as an anthology than as one fluid story.
Also, let's all remember that the only reason ANH and indeed the OT ended the way they did was because in 1977, Lucas had no idea if the idea would be successful and wanted to be able to make ANH stand on its own in case he didn't get to make more movies. Then ROTJ ended the way it did, because Lucas only planned on using the strongest part of his "saga" to start, because he bankrolled each movie, and wanted a strong footing for LFL to stand on. Only later did he go back and begin making the rest of the the story. So he started at the beginning with the PT, and when the reaction to that was so negatively strong, it killed his interest in making SW movies, which is why he let the EU run its course, and only acted as producer for the TCW series before he eventually sold the property to Disney.