Star Wars has always had a huge British element to it (from the Empire being based on Imperial England, to many actors being British and much of the filming/production being done in England). Lucas, at times, gets too much credit and not enough blame (IMO). His writing has always been a bit clunky - his ex-wife cleaned up a lot of the dialogue in the original trilogy to make it work. She did not work on the prequels and it showed.
You also can't really say anything past 1981 strayed from his vision when then prequels (1999-2005) were 100% him and they were no where near as good as the original trilogy. The original series had different directors/producers and such so that wasn't a huge change (those 3 films each had a different director, 2 different producers and 3 screenwriters) but Lucas was there to handle the overall story for the first 6 movies, which the last 3 did not.
I think the last 3 films could have been better if there was some continuity off the screen in overseeing the story to make it consistent. They started out good on that path by bringing Lawrence Kasdan (co-writer on Empire Strikes Back & Return of the Jedi) to co-write The Force Awakens so they fit well with the original trilogy. Abrams was offered The Last Jedi but turned it down (because Disney's schedule had no time off between filming the projects & he needed a break) so they brought Rian Johnson in. Johnson had no connection to the series and he had his own vision, so he went in a different direction with some things. Abrams came back for Rise of Skywalker but now had to to tie his original story into what Johnson had done and it wasn't great as a result. I think if Abrams had been able to do all 3, it would have been much better but we'll never know.