I fully disagree that there was nowhere to go. I just think that the place to go was a place nobody was
prepared to go, and that is...
...BEYOND THE LIMITS OF TRILOGIES......
Seriously, the
story had plenty of places to go. Just not places where you could tie everything up with a bow and have the good guys win in a single movie in any manner that is convincing or satisfying. To do that, either you time-skip ahead, or you massively empower the good guys as a short cut to the longer build-up necessary to make it work. And hey, TROS did both! Yaaaaaaaaay....
But consider for a moment what the alternative could have been.
- The next film starts with Snoke dead, and Kylo Ren having been humiliated at the Battle of Krait (such as it was). Luke Skywalker's whereabouts remain unknown (at least to the wider galaxy), but the (New) Rebels have escaped. Meanwhile, the First Order seems triumphant, having all but completely eliminated any serious opposition to it...and yet, the spark of rebellion still flickers in the darkness.
- Kylo Ren seems to be in control, but having "killed the past," he now lacks direction for the future, and has to face down multiple attempts by his underlings to oust him, until he is finally thrown out by a council made up of the Knights of Ren, Gen. Hux, and several other high-ranking First Order characters. He's beaten badly and left for dead, stranded and on his own.
- Contrasted against Kylo Ren's fall is the gradual building up of the new Rebellion as they gather their forces and rebuild. Leia hands off leadership to the new heroes (Poe, Rey, Finn). The new film culminates with them securing a significant victory against the First Order that shows the New Rebellion is still alive and a force to be reckoned with, and which sets up...THE NEXT SEVERAL FILMS.
- Over the course of the next 2-3 films (OR HOWEVER MANY IS NEEDED TO TELL THE STORY EFFECTIVELY), the New Rebellion fights against the First Order, while the First Order suffers from having both "won" as well as its own infighting and power-plays. Where the New Rebellion is united and cooperative in its efforts, the First Order ruling council is made up of self-serving backstabbers just waiting for an opportunity to advance their own personal power, all with the goal of becoming a new emperor. Meanwhile, Ben Solo gradually rebuilds himself and serves as a kind of anti-hero, fighting the First Order, but not aligning with the New Rebellion. He basically undergoes a "face-turn" and sacrifices himself in the end to help the heroes achieve victory.
- Consistent themes are "evil always devours itself because it only knows how to destroy" vs. "good survives because people come together to keep it going." You could then take multiple films to build back up to a truly worthwhile finale, and -- best part of all -- NO PALPATINE!! Maybe you could have, say, Palpatine's DNA be some macguffin at some point (or I guess his "midichlorians" or whatever), but it's all just a macguffin and not him as the final boss villain, which was incredibly lame and myopic. You could also explore a new Jedi order that isn't anything like the old one. More tied into emotion rather than shunning it.
Thing is, you absolutely can't do any of this in a
single film to wrap up a trilogy. It'd take multiple films, but you could tell a good story. But no, they wanted a cookie-cutter "just like we did it before because that's how we did it before" approach, and we got what we got.
One other point I wanted to make:
It's not a plot hole that Rey is incredibly strong. She could just be a "vergence" in the Force, which is addressed in other Star Wars media (which remains canon, I should note). She doesn't need to have a powerful bloodline.
The "mystery" around her parentage never made sense anyway. It would be a "mystery" to the audience, but not to Rey. She knows who her parents are, or at least who they were to her. Retconning her into a Palpatine was just beyond stupid. There are more than two families strong in the Force in Star Wars, but you wouldn't know it to watch TROS.
Regardless, what matters for viewers and for the character is not "Where do her powers come from?" but rather "What choices does she make and for what purposes does she use them?" Rey's a Palpatine! Rey's a Kenobi! Rey's a Skywalker! Rey's a rando! Rey's a vergence! Rey's a clone of an ancient Jedi master! Does any of it matter? No. That's the point of TLJ. Rey's parentage is a distraction and is meaningless to the story. What Rey does with her power is all that matters.