Firstly I’d like to mention The Lost Fleet series by John G Hemry. It’s military sci-fi, as a part of the plot it discusses two forms of FTL travel, jump drives allowing you to FTL between adjoining stars, and the later invention of hypernet gates allowing direct travel from one star to another. It talks extensively about how certain star systems fared after hypernet gates made it unnecessary to travel through them to reach higher value systems.
Some star systems were only inhabited as a means of supporting various cargo haulers, transporters, and warships that must pass through those stars. As pass-through travel waned we saw declining economies, civilians abandoned as extraction costs would have affected profit margins, increased societal unrest and rebellion as a result of being cut off from the central authority, and various other legal and illegal activities.
It illustrated how truly huge space is, and how difficult communication, transportation, and protection could be out among the stars.
I’d also like to provide an honorable mention to Malazan - Book of the Fallen, even though it’s high fantasy.
This is because it not only goes in to significant detail regarding the magic system used, but also talks several times about the societal stagnation that comes about as a result of reliance on magic, and the reduced need to invent, discover, and innovate. The lack of science, and the implications of that, being the point here.
Gives real “A QA walks in to a bar and order -26 beers” vibe