Both.
In seasons 4-7 Voyager was pretty much the Janeway-Seven-Doctor show, whereas in the first two seasons all the characters got good screen time. That dragged down the show terribly. But, in season 3 the show had gotten terribly stale and they were reaching for story. They had dinosaurs evolve into a super-race, for chrissake. Seven revitalized the show and made it interesting again.