I don't understand why people act like the prequels needed to tell the exact same story as the originals. The original Star Wars is held up as some sort of flawless perfection, which is a rather ridiculous notion. Have you ever seen Kurosawa's The Hidden Fortress? It is the exact same story, created decades before George Lucas filmed a single scene. I bet that if TPM had been released in 1977, people would be just as devoted to it as they are to the original Star Wars. None of the stories are original. ANH just has had the advantage of being around for 35 years.
There is a great deal that is wrong here. I'll take it one sentence at a time.
I don't understand why people act like the prequels needed to tell the exact same story as the originals.
Who are these people? I've never encountered them in real life or online. If anything, I've encountered fans who think just the opposite, that the PT rehashes elements of the OT
too much (for example, R2 and 3PO together on Tatooine at the Lars homestead

, the throne room on the Invisible Hand

).
What I wanted was backstory that made sense, and I wanted to feel like the PT was showing me things alluded to in the actual OT. The PT failed on both these accounts.
Now, I'm not a PT hater. It's just that I rank the PT only with second tier films, while the OT is top notch.
The original Star Wars is held up as some sort of flawless perfection, which is a rather ridiculous notion.
People who say the OT films are literally flawless are indeed blinded by their admiration. But then again, who are these people you are referring to?
To say that it is irrational for someone to like the OT better than the PT, because the OT is demonstrably not perfectly flawless, is a perfect example of a straw man fallacy.
Have you ever seen Kurosawa's The Hidden Fortress?
Yes.
It is the exact same story, created decades before George Lucas filmed a single scene.
George Lucas frequently cites
The Hidden Fortress as a major inspiration.
I bet that if TPM had been released in 1977, people would be just as devoted to it as they are to the original Star Wars.
Bullshit.
For one thing, if
The Phantom Menace had been made in 1977, the special effects would have been made using the technology of the time. That means, for example, stop motion, models and blue screen, optical printers, hand-painted static matte paintings, puppets, makeup, and
no CGI.
Getting Harryhausen himself to work on the effects would have likely been impossible, since he was working on
Sinbad and the Eye of the Tiger, and this would have hurt the film even more.
The number and complexity of the effects shots would have been drastically reduced. Given the budget of around ten million dollars, I'd say there's an excellent chance that the movie never would have been completed in the first place. If you know your history, then you know that Lucas was scrambling just to get the first film completed on time. Many of its effects shots were seriously flawed (e.g. the landspeeder).
Furthermore, since the effects would not have been able to carry the movie, the flaws in its story would have been even more apparent. I believe that from the standpoint of the culture at large, it would have blended in with all of the other fantasy movies of the time, like the Sinbad film, which today are all but forgotten.
And without blockbuster momentum, the sequel budget would have been
less than that of the original, and the series would have died with the second film, assuming it was even made.
None of the stories are original.
Well, if by this you mean that none of the stories are
entirely original, then that's true. But so what? Quite obviously, in 1977
Star Wars showed its audience something they had never seen the likes of before, and something they wanted to rewatch again, again, and again.
ANH just has had the advantage of being around for 35 years.
Being around for 35 years doesn't explain why
Star Wars was so monumentally successful
at the time it was released. It practically defined the concept of a blockbuster.