This might be related to this question
It is quite characteristic for fantasy worlds to have little technological progress because magic (since magic works better than technology, we don't need to develop it) and/or longevity of one of the dominant species (longevity means slow reproduction rate which leads to slow "I want to do things different than my parents" type of progress).
In SF technological stagnation is usually explained by some great catastrophe that created new Dark Ages (i.e. Canticle for Leibovitz) or we have something that actively prevents innovation (like risk of Chaos possession actively discourages too bold innovations in Wh40k universe or risk of re-creating Thinking Machines in Dune).
In the Star Wars we do see progress between episodes with the Death Star as a best example (there are other mentioned in linked question: change to space fighters, upgrade to the bionical replaced limbs - compare Anakin's and Luke's hand), but when you look back and notice that technology from the Old Republic (i.e. in the KoTOR games) is not that much different than one in the movies, yet there are separated by few thousand years. As someone that is not very knowledgeable in the SW universe outside of the basic movies, could someone tell me, why there is so little progress? Was there a regress in-between or simply people gave up after reaching some sort of peak (like it happened towards the end of the Roman Empire)?