People are too obsessed with the idea of trilogies. Honestly they should have never bothered numbering the Star Wars movies at all, and should have just filled things in with whatever movies they wanted to make. So like, for instance, they could have just made a bunch of movies about young Anakin at different stages of his life, or about other characters in that time period (which could feature Anakin as a supporting character or guest character), and we wouldn’t know the exact one where Anakin would turn to the dark side, but we would see the gradual transition. And then a later movie could just be about him hunting down Jedi. Others could be about other characters, like Obi Wan.
I mean that’s eventually what the Star Wars meta narrative evolved into, when you factor in Clone Wars and all the standalone movies and Disney Plus shows. There’s no reason they couldn’t have just written things that way in the first place, instead of forcing the prequels and sequels to mirror the OT.