"On Earth, there is no poverty, no crime, no war. You look out the window of Starfleet Headquarters and you see paradise. Well, it's easy to be a saint in paradise, but the Maquis do not live in paradise. Out there in the Demilitarized Zone, all the problems haven't been solved yet. Out there, there are no saints — just people. Angry, scared, determined people who are going to do whatever it takes to survive, whether it meets with Federation approval or not!"
I always assumed that by the time of Voyager, replicator technology was advanced enough that they could perform any repairs necessary as long as they had enough power.
That said, I think Voyager would have been a better show if the whole show was done the way Enterprise handled the Delphic Expanse arc. Voyager getting more and more damaged as time passes would have really hit the "far from home" vibe.