Luke’s perspective on balance is this: when the Force is simply allowed to exist as it is (light and dark among it), the universe is at balance. He says that “for a time there was balance,” after the events of ROTJ. But he believes that him trying to rebuild the Jedi order pushed the scales, and it is what caused the dark side to return.
Of course this is just Luke’s interpretation. It’s the whole reason he believes being on the island is the right thing to do.
It seems like you think all the bad parts of Star Wars tie back to the prophecy, when I never interpreted it as a retcon of the OT.
I mean, whether or not you think it works, it is a retcon of the OT.