I never said they never improved it, but they did steal it.
Aqueducts pre-date rome.
Judicial processes and law pre-date rome.
Masonry pre-dated rome
Bound books pre-date rome
Arches and domes pre-date rome
Concrete pre-dates rome
Yes, they may have made incredible versions of these things, maybe even the best versions of these things (we just recently started unlocking the secret to roman concrete longevity) but when I was growing up, I was falsely taught Rome created many of these things whole-cloth, with no other civilization contributing anything. Which is an annoying bit of erasure, because you don't need Rome to have been super-geniuses who invented half of modern architectural ideas for their work to be impressive. And it lessens the work of the those who actually DID invent these things, and leads to stupid theories about how such and such ancient structure had to be built by aliens or something because only the romans had X or Y technology and they weren't even around yet to invent it!
To lay this in some more concrete terms, I don't need to say "romans invented shields and armor" to highlight how cool and well-designed roman shields and armor were, so why do I need to say "romans invented aqueducts" to talk about how well-designed their aqueducts are?
And to tie this back to the original point, the fact that the Romans would steal and incorporate ideas, while having a massively inflated ego about their own society (not undeserved, but inflated) should give us pause when considering their definitions of what "uncivilized" people were like. Because to the Romans, all non-Romans were uncivilized. But that doesn't mean those other societies weren't, you know, societies and civilizations.