Star Wars is exactly a generational problem. Say you were 10 when Star Wars came out in 1977, you're 52 today. If you were 10 when Phantom Menace came out, you're 30 today. If you were 10 when Force Awakens was released, you're 14 today. A 52, 30 and 14 year old have very different expectations of what they want out of Star Wars. Doesn't necessarily make any of those people wrong, it's just a different set of nostalgia. I grew up with the Kenner toys and seeing the originals in the theaters. I remember the dark time post-Return of the Jedi when no one cared about Star Wars anymore. I remember the extremely disappointing Prequels and now I have the experience of watching my young boys fall in love with Star Wars.
The true test of the franchise will be Rise of Skywalker. Historically both Empire and Attack of the Clones had dips after the first in the trilogy and the third movie had a bump up. If there's another drop off, then Disney has reason to be concerned. Solo was an abnormality. It had very little marketing in a very short window of time and followed one of the biggest event films in a decade (Infinity War). I think it if maintained the December release, it would've been much more successful.
Personally, I think Star Wars biggest problem is China. Until they can break in there, they're always going to fall short. A new series with new characters and original plots might help that considerably.