@alyx i think a lot of that has to do with the fact that most of the action takes place on board ships

empire was a bit the same way except it had lando calrissian and cloud city to help expand it a bit. the casino planet tries to do that but does feel very limited in comparison

fwiw i think the ending (for me at least) pointed to a very expansive galaxy and a world far beyond the immediate cast. i hope they make good on that in the next movie or even the next trilogy