It really wasn’t an origin story so much as how Han met Chewie and got the Falcon, and we’ve known how he won it since 1980. The later Han Solo novels were much more lengthy and detailed in Han’s history than this movie. This was just a fun adventure like the early Brian Daley novels, which I’ve loved since I was a kid.
Are superheroes ruined for you because you know how they got their powers or decided to fight crime?

If any character’s origin is mysterious, it’s Yoda, and should remain so. And they’d better not de-mystify the Force by explaining that…oh crap…