I can see why TFA went back to basically retell A New Hope - because that original story is powerful and just works. If you want to relaunch your franchise, you have to realize its strength. What captured a wide audience back then will capture a wide audience now. It is really secondary if this is particularly appealing to old fans or not. It's appealing to audiences in general.
The key problem that I had with TLJ was actually something carried forward with TFA, but which I didn't fully understand or grasp then. TFA was mostly disappointing to me since it felt like a retelling of A New Hope, and I've seen that story already. But the new characters seemed likeable, it was a good idea to not pick Kylo Ren that the movie is trying to sell me as someone even nastier than Darth Vader, but is actually a "wannabe". That was kinda couragous, but also kinda sensible, because you can't really one-up Vader. And having a new force sensitive hero go from nothing to Jedi looked promising. And I like female protagonists. Making another protagonist an Ex-Stormtrooper was also interesting, we hadn't really seen much of that side of the world.
The problem is that the heroes of the original trilogy are basically turning into failures. They didn't beat the Empire, it is still strong in the First ORder, and it's blowing up their world. Han and Leia didn't stay together, they split over their son turning to the Dark Side. And Luke Skywalker didn'T really embrace his Jedi heritage, he gave up on it, and he abandoned his sister and best friend and the Republic in the time of their greatest need.
It wasn'T quite as in the face in TFA, because in TFA we could still pretend there was maybe a good reason for Luke hiding away. But TLJ's reason for it just isn't satisfying.
I think one probably could tell a story where Luke Skywalker gives up on the force. But it would be its own movie, not a quick flashback, if you want me to believe and accept it.
There were other problems in TLJ that really were just TLJs.
The Momma/Telephone joke in the beginning was just too absurd, and a lot of the initial battle - and later parts of the movie - relied on the heroes and villains being incompetent. The plot on Canto relies on luck (of course, they don't find the hacker they seek, but another guy that is just as good) and incompetence (they land their shuttle in a forbidden zone), plus nonsense (animal slavery is apparently worse than child slavery, plus what is stopping anyone from capturing the animals?). The mutiny on the Resistance ships seems to only happen because the leader can't communicate with one of the more influential and respected officers.
Maybe it is rose-colored glasses, but except for the Storm Troopers constantly missing in V and VI, the Empire and the Rebellion seemed to be fairly good at the things they are supposed to be good at.
The troopers shooting in Episode IV is actually understandable - the Millennium Falcon got a tracker installed, so the rebels needed to escape to lead the Empire to the Rebel Base. Han or Luke not being qualified to run an extraction on the Death Star is not surprising - but they did fairly well.