I find it strangely dissonant that you dismiss TFA and TLJ as “nostalgic cashgrabs” and “corporate fan fiction”, yet you say you “loved” Rogue One.
Contrary to your opinion, I thought that TFA and TLJ while they do play on nostalgia, had a lot more heart than Rogue One, which I felt was a soulless assembly of recognizable imagery built around hollow characters.
TFA and TLJ add nothing of value to the saga of I - VI, Rogue One does.
The characters in Rogue One may be very underdeveloped, but at least they’re actual characters with flaws and personalities, and not Cliche Two Dimensional Character #1, #2 and #3.
If you’re talking about plot-wise, then I agree Rogue One does add more to Star Wars. Though I don’t know how you can say that neither TFA nor TLJ add nothing of value. Yeah, Rey is kind of a blank slate, an avatar for the audience. But Kylo Ren directly informs the characters of Han, Leia and Luke. We get to see how they’ve changed since the OT. What those movies lack in plot (and they do) they make up for with story and conflict between characters.
Rogue One is the opposite. It’s all plot, no character conflict. Between some of the characters, there’s almost no interaction at all, which makes me question their purpose in the movie. They each have their own character traits (mostly just their jobs) I guess. But saying they have well defined personalities is a stretch. Donnie Yen’s character was the only one with any personality at all.