But you could say the same thing about Episode IV, couldn't you?The bottom line, to me, is that TPM as one-third of a trilogy that had a LOT of ground to cover in a reasonable way to be successful just didn't "pull its own weight" in terms of adding to the overall saga.
Qui-Gon and Darth Maul die, we never see either again
Next time we see Anakin he's ten years older and a completely different character, personality-wise
Jar Jar Binks, who gets a LOT of screen-time in TPM, is progressively less relevant in each of the next two movies
So much stuff that's in TPM just turns out to be irrelevant filler
Tarkin, the main villain of the movie, we never see or hear of again.
The destruction of Alderaan has absolutely no consequence whatsoever.
The Rebels blow up the Death Star, the Empire just shrugs and builds another one.
Next time we see Ben, he's become an Exposition Ghost.
A lot of time is used to introduce us to Tatooine and its inhabitants, only for it to become the backdrop of the escape sequence in Episode VI.