For my part, I thought Solo was better than most claimed -- definitely better than Force Awakens or The Last Jedi. And @Matt Bellamy hit the nail on the head in regards to why I didn't like it: the characters. Specifically, in my case, the new characters.
From the beginning, Poe came across as a poor man's attempt to blend Han and Wedge Antilles. He has some moments where the characterization tries to be interesting, but by and large the performance comes across as uninspired. The Last Jedi only made things worse, with having him lead a mutiny of sorts. It just felt jarring at best.
Next up: Finn. For an ex-First Order stormtrooper, he's surprisingly rogue-ish, and I don't mean that in a good way. Throughout Force Awakens and most of The Last Jedi, I didn't care for him -- he was all about saving his own skin, and to hell with anyone else. Now yeah, that's a lot like Han during A New Hope, but taking most of two movies before he finally has a moment where he's willing to sacrifice himself for the greater good -- only to be metaphorically screwed out of it by Rose (who spent most of the entire movie complaining about how he was only looking out for himself and didn't care, only to then turn around and keep him from having what I felt was his first heroic moment)… ugh. And the fact that Finn spends part of two movies playing around with a lightsaber when he has no business touching one, let alone actively wielding it... I can only eyeroll so many times. That said, Finn's still at the best place right now of the three characters I'm outlining for this, but this is a low bar I'm setting.
And then... there's Rey. Let's be honest here: "The Last Jedi", in my mind, refers to Luke. It does not refer to Rey in any sense, and I'll get to why shortly. Rey was written to be Disney's version of Kyp Durron from the Expanded Universe. She's pretty much completely ignorant of The Force... and yet can Jedi mind-trick stormtroopers and do several other Force abilities without any semblance of training in Force Awakens alone, and can defeat (and injure) Kylo Ren with zero training with a lightsaber. She's the Mary Sue of Mary Sues*, and The Last Jedi only highlights the problems with Rey as a Force-user all the more. While believing that there's still some good in Kylo Ren is noble, it's about the only noble thing Rey has going for her. The way she fights in both movies, she's far more of a Sith than she is as a Jedi -- every lightsaber duel she's been in, and for that matter, most every use of the Force that Rey has shown thus far, stems out of fear, anger and aggression. She's closer to being the embodiment of the Dark Side of the Force than to anything else, and I don't see how she could actually be seen as any sort of hero by the end of Episode IX.
I'll leave out the other nitpicks about how Leia's doing effectively the exact same thing as Rey during The Last Jedi when she does her Force Flight in space to save herself when she should have been dead, or how Luke was worthy of taking over as the replacement for Oscar the Grouch on Sesame Street and all that. A lot of the problems come down to the directors and their narrative "vision", and everything I've seen so far tells me that J.J. Abrams should never have left television, and Rian Johnson having creative control over a trilogy of his own making after the craptastic job he did in The Last Jedi is a bad idea.
But in the end, I think Disney has to shoulder the blame as well. There's no mistaking the fact that buying out Lucasfilm in 2012 was exactly what most people feared it to be: the ultimate cash-grab. They're about to do the same thing again with acquiring Fox -- the only difference is that they can at least try to integrate the X-Men and Fantastic Four back into the MCU. But it's clear that Disney never had a long-term plan for the Star Wars franchise other than "lets make six movies in the next 7-8 years and recoup our financial losses" -- if they thought Star Wars could be another MCU-like springboard, they've done a lot to cripple themselves in that regard. And let's not forget the waffling back-and-forth about how they publicly said they weren't using any of Lucas's planned material for the sequel trilogy, and yet have tried convincing the public in the wake of The Last Jedi how they actually were using some of Lucas's material after all (which I think was a backhanded attempt at throwing shade at Lucas after how critical he was of Disney's plans, in part because of his own claims that Disney had no plan to use any of what he developed for the sequel trilogy).
If there is a silver lining to all of the missteps that have been made since Disney bought the franchise out, it is this: they've managed to make the prequels look so much better than anything they've done. And I say this as someone who actually does enjoy the prequels, in spite of their flaws. But aside from Rogue One and Solo... I haven't been able to enjoy the sequel trilogy in the slightest, and I don't have faith in Disney (and I certainly have no faith in J.J. Abrams or Rian Johnson) to be able to make Episode IX watchable.
* I do want to note, I'm not against strong female protagonists in the slightest. I only have issues when it becomes blatantly obvious how much of a special snowflake that Rey was written to be. I'll also note, more generally, that I don't have any issue with the actors/actresses playing Finn, Poe, Rey, Rose, etc. -- their writing is what fans are (rightfully) up in arms about... but that doesn't give those same fans the right to bully/harass any of the actors/actresses for portraying the role they were given. If the fans want to take issue with the characterization, they should be aiming those crosshairs at Disney, J.J. Abrams, Rian Johnson and the writers for the screenplays for both Force Awakens and The Last Jedi.