Battlestar Galactica fell apart after two seasons, and the only way they were able to get the show to work was:
1) Have the survival of the Colonials actually be meaningful. If they die their entire civilization is gone. Not so with one insignificant Federation starship with no importance to the Galaxy.
2) Have humanity be the ONLY life in the Universe. Only them and the Cylons, no other aliens. This would make NO sense in Trek.
3) The Colonials had a magic teleport machine that couldn't be tracked. If VOY had some magic device (like a cloak that even the Borg couldn't detect, or a teleport drive no one could detect) then they'd have an advantage the writers could use.
4) Cannon fodder, they had an armada with tens of thousands of nameless faceless extras to kill off without harming the Galactica or the main characters.
I think you're greatly overestimating costs. CGI isn't a typical resource. It's cheap, it doesn't need to be rationed, and it's easy to reuse. We DID see plenty of new CGI models. There's no reason some of them couldn't have been more repair stations etc.
CGI only got cheap halfway through the series, not from the start. They were still using physical models for seasons 1-3 (around there) and the CGI models they were able to use for Seasons 4-onwards were pretty expensive. Even DS9 didn't alter their CGI models. The Defiant was always in pristine condition throughout the show until it was destroyed and then they just got a brand new type of the same ship.
That's fine, but you can't really make this suggestion while simultaneously defending what they did do. That would have been a completely different story.
I'm suggesting they just assume the audience really are a bunch of morons who need to be spoonfed everything.