“Rich characterization” is wildly overrated.
I can think of so many cool movie characters from the past that had little to no backstory or arc.
Take a movie like Aliens… what the hell do we know about Vasquez? Drake? Hicks? Hudson?
Or Predator… Pretty much all of the characters are totally paper thin and the movie is still awesome. “This stuff will make you a sexual tyrannasauras” What more do you need to know after that?
There’s plenty of thin characters from the OT that were cool - Boba Fett (until he died like a chump), Piett, Veers, Tarkin, Admiral Ackbar
Admiral Raddus from Rogue One was cool.
Anyways… just saying it’s completely possible to create cool and compelling characters without wasting a bunch of time on backstory as long as you can get some good acting and a well written script.
Honestly - Darth Maul was one of the only cool villains in the PT (the other being Palpatine). Both of them were simple black/white characteers… but they were well acted and designed.