I think a more accurate way to say it is that writers of prequels really don’t like to be beholden to established narrative beats. Is the new stuff they come up with also predictable? Sure, oftentimes it is, but I think the writers at least feel like they are doing something new when they deviate and twist background details in unintuitive ways. Like, the prequels could have easily just not had the droids or Boba Fett at all, leaving them instead to the intuitive, straightforward origins we can infer from the OT. Their entire prequel backstory is basically one big “I bet you didn’t expect THAT to be where they came from!” contrivance.