what Lucas did took real guts. he fully believed in his vision. there are so many wild and idiosyncratic choices he made when devising the original Star Wars. yes, his source material was indeed comics (he was inspired by Fourth World & 60's psychedelic Kirby stuff), pulp science fiction (Leigh Brackett, writer of the first draft of ESB, had written a story with lighstabers in it during the 1940s), spaghetti westerns, japanese films, war movies, etc. C-3PO and R2D2 were nothing more than references to the Hidden Fortress, as Star Wars was originally a remake/reboot of that movie, and the two traveling lowly peasants were transformed into the iconic droids that would basically live to see (and tell) the full events of the series. all these things were his source material. SW only exists because he would take a character from a comic or movie he liked and twist it into a new thing, be it a robot, an alien, etc. the new folks don't even try to do this, they spend all their time commenting on the old stuff, and complaining about how hard it is to get paid millions of dollars to play with someone else's toys.
JJ and RJ and others have been graced with an embarassment of riches, and all they can do is throw their toys at the wall. it is not difficult to just come up with a new Jedi, a new furry alien friend like Chewie, a new robot duo, hire an esteemed older actor to play an Obi Wan type, a new lovable puppet like Yoda, etc. instead they took the old ones and made it about them, and then they told us "this isn't about the old characters, quit caring about them". if instead of Chewbacca it was Chimbo then that dumb Porg comedy scene wouldn't sting so much. they just failed at even trying anything new. where is Rey's spaceship? or a new lightsaber like weapon? where are the new non-TIE Fighter non-X-Wing ships? they just going to do slightly bulkier Star Destroyers, no new designs? they could have easily invented new things. they chose not to. Admiral Holdo is just a Bad Rebel Commander who subverts by NOT telling everyone the plan in a holographic conference room (every previous SW film have gratuitous scenes of commanders explaining & projecting vital data to everyone involved, even random smugglers). Rian did not give us anything new, he gave us a poor twist on a known character type.
really, Rose is the only new part of TLJ, and she is practically a bipolar fascistic militant designed purposefully to be unlike anyone who would be in a Star Wars movie. her first scene has her tasing the black male lead in a disturbing moment where his loss of agency is played for comedy. you think back to the very first SW film, where C-3PO and R2 kick off a whole series of adventures by doing what Finn was trying to do, fleeing on an escape pod. but here it's bad, trying to help your friends, trying to get away from violence. the Resistance is basically acting no better than the Empire used to be, as demonstrated by Rose, in her debut scene. later she lectures a former child soldier "(and us) on the perils of capitalism before they introduce the idea that maybe both sides really are the same (DJ). moral relativity has poisoned a series which once had pretty clear & archetypal moral lines drawn. the new people writing these just aren't good enough to write those kind of mythical tales.
indeed, the true rot is just bad writing. even taken at face value, these movies are houses of cards, precariously built on well designed trailer worthy images based on images from 40 year old films. the writing, the character arcs, the dialog, all of it is incoherent. i cannot find myself caring about any of the characters after the last ST film. TFA was ok if you shut your brain off, TLJ had such a big ego it dared you to question the shit you were consuming, and i found the ST lacking in it's entirety. they aren't even trying. if they are having trouble making these, it is difficult because the people she has chosen are not capable of doing a good job.