I’ve gone back and forth on the prequels a lot over the years. I have very mixed feelings on them, but they’re fascinating movies to pick apart.
The OT works because it got general audiences invested in its characters. That’s why it caused reactions in the theater like this:
https://www.youtube.com/watch?v=PzRveOGMflo
Star Wars movies only really work when they’re character-driven, and when you have compelling heroes and villains that stick out in the audience’s minds. There isn’t really an exact formula for how to achieve this, and I think George tried his best to recapture that magic when he made TPM, but failed.
At the start of ANH, R2 and 3PO are our audience proxy characters that we follow, up until we meet Luke, who then becomes the primary POV character. R2 and 3PO have great chemistry as they play off each other, and adults and children both enjoy their back-and-forth, even after the main POV shifts to Luke. Meanwhile, the film’s plot centers around Leia, and the film does a good job of getting us to sympathize with her plight while also seeing how bold and resilient she is.
In TPM, our initial POV is Qui-Gon and Obi-Wan, who are very stoic and flat, outside of an occasional snarky comment from Obi-Wan. The central character, the Queen, is also very stoic and flat. Then, the role of audience proxy is filled by Jar Jar, which, in theory, isn’t a bad idea, except for the fact that it’s…well, Jar Jar. Unlike the droids, his appeal as a character is to a much narrower demographic.
I think George realized the cast was too stuffy and stoic, so he tried to counterbalance that with Jar Jar and kid Anakin, but the result is that we get two extremes with little balance or chemistry between them. With the OT, the main hero characters had more of a balance between serious and lighthearted, which endeared the audience to them and allowed for people to latch onto those characters and their relationships.