I don’t really see why every character needs a backstory. When the whole point is to make a standalone movie where none of the characters will return in a sequel, the I don’t really see how backstory would be necessary unless directly related to the plot, e.g. Jyn’s relation to Galen.

I think RO can be fairly compared to movies like f.ex. John Carpenter’s The Thing in terms of how the characters are developed. What’s so brilliant about the writing of that film is that it never wastes any time explaining anyone’s backstory. All that we need to know about those characters are revealed to us through how they all cope with the same intense situation. There was never a “when I was a kid…” or “back home I was…” type of dialogue, all that we need to learn about their personalities comes from how they react to the crisis that is at the center film. That in my opinion is good economical writing. Granted, this method is not for every type of movie, but I think that this is the kind of story that RO tries to be. Which makes sense when you got a war movie focused on one specific threat and one specific important mission. RO isn’t really a “character film”, yet it still manages to explore several characters’ personalities and implied backgrounds based on how they behave throughout the story.

Also SW does have the benefit of having one of the most elaborate EUs in existence, so if you are just dying to know the life story of Chirrut or Bodhi, or any other character, I’m sure there’s going to be some novel or comic that will explore this at some point.