Garbage in the Star Wars universe probably wasn’t explicitly outlined in the same way that trash remediation is IRL. The general idea with compacting trash it that you maintain the size of the container, but cram as much garbage into that volume of space as possible (cramming crap farther into trash can to make a little more room on top), thus reducing the number of times you have to deal with a trash container vs. amount disposed of.
Why the heck did they compact their garbage if they just eject it into space anyway?
Garbage in the Star Wars universe probably wasn’t explicitly outlined in the same way that trash remediation is IRL. The general idea with compacting trash it that you maintain the size of the container, but cram as much garbage into that volume of space as possible (cramming crap farther into trash can to make a little more room on top), thus reducing the number of times you have to deal with a trash container vs. amount disposed of.