Mate, I don’t know why it’s so hard to understand, yes JJ had very, very little input into Last Jedi, from the man HIMSELF. JJ has said this. Unless you’re suggesting JJ is lying about having no input into Last Jedi?
And I don’t know where you’re getting this JJ did everything from? The 3 films were NOT all written by JJ Abrams. This is Disney’s triology not his. He wrote Force Awakens with help, and that’s it. They can’t have been all written by him, there was separate writing processes for each movie, and JJ said HIMSELF that he basically had no input into Episode 8 and let Rian Johnson do what he wanted to. Rian Johnson wrote and directed and basically did everything for Last Jedi. They’re still writing episode 9 now, so no, JJ definitely did not write all 3 movies. In fact the reason they fired Trevorrow as director for Episode 9 was because his writing was apparently bad and he was full of himself going past arrogant and was impossible to work with, and him and Disney just hated each other. Also his bomb movie about ‘Henry’ beforehand didn’t help things in their eyes.
Kathleen Kennedy, thanks to Spielberg’s nomination selected JJ as director for Force Awakens after JJ initally refused but was convinced to do so thanks to his wife. He wasn’t even logically possible fora single director to do all 3 movies, that’s over 6 years straight of continuous shooting and script writing, hence why they announced 3 different directors in the first place. Peter Jackson is one of the few directors to do 3 movies back to back like that and even that was 3 years apart per movie, this was 2 years. He barely wanted to do the first 1 initially.
Your defence of Rian Johnson makes no sense in your context. THE STORIES FOR ALL 3 MOVIES WERE NOT ALL WRITTEN BEFORE FORCE AWAKENS AT THE SAME TIME. JJ wrote Force Awakens with help after going from early draft script ideas (that were mostly tossed out.) Rian Johnson wrote Last Jedi. Trevorrow was writing Episode 9 until recently. So Rian Johnson can’t go against this so called plot that was already written when he wrote the damn movie himself.