All three of the sequel movies are really bad IMO (and no that's not intended as an insult to people who did like them, you're entitled to your opinion). At the time it released, I considered 7 to be just "mediocre", it opened up a lot of questions that were very contingent on the sequels following through in a satisfying way. But 8 and 9 actually managed to retroactively make it worse. It's not often I see a case where my opinion on a movie can be altered based on the quality of the sequels. But so much of 7 was dependent on the sequels that, when they failed so spectacularly, 7 was also dragged down even lower in my view.
Original trilogy is never going to be topped, I watched the new 4K Disney+ transfers with my mom earlier this year (via a projector and a large wall, so it was a semi theatrical experience). She's only ever seen A New Hope all the way through of the OT. She's also not a big fan of the franchise as a whole, but she found the entire OT fantastic.
The prequel trilogy is often very stupid due to the childish comedy, ugly overused CGI characters, stupid dialog and bad acting. And yet they are still very entertaining movies and there's a good plot buried below the surface. The action is also generally great too, especially the lightsaber sequences. I also think it has the most interesting and exotic environment design in the franchise and wish the theme park land had borrowed more from those environments. I'm not bored while watching these movies, even if I wish Lucas had someone to reign him in. A "competent" yet boring movie is a worse thing for me than a stupid yet entertaining one.
The sequel trilogy is an example of the "boring" complaint. They're not as "stupid" as the prequels (at least not in the same way) and are more competently acted. But they don't have an interesting plot hidden below the surface to help carry them, nor is the action very good. They aren't fun or entertaining movies. Hell, even Ian McDiarmid isn't given anything fun to really work with.