I think the big thing that makes Star Wars aesthetically unique among sci-fi settings is that it all has the look like its form had to be constrained by its function.
Like an engineering team were operating under conditions that required some sacrifices of aesthetics/symmetry for the sake of utility in the final product.
It's something that you see all the time in real vehicles and machinery but that's kind of rare in sci-fi (and in Star Wars it might be partially because they kitbashed everything out of things like old cameras, engine parts, and model kits).
Even the lightsabers, the “elegant weapons from a more civilized age,” just look like a random piece of machinery with buttons and knobs jutting out at odd angles (aside from the fancy ones in the prequels like Mace Windu’s).
