NuBSG had cheats that VOY didn't have:
1) They never had to restock weapons after the first episode. No one complained. Yet everyone complains over VOY having torpedoes.
2) They could make new Vipers, but folks couldn't believe VOY could make new shuttles.
3) They had a big fleet in VOY to pull new crewmembers or characters out of nowhere, yet when VOY tried to make recurring characters everyone complained they shouldn't have any.
4) NuBSG's damage was all window dressing, it never impacted the core working of the ship, it was just scars on the outer hull.
As for Voyager in "Year of Hell", they only had the money to make the changes for that story. It wasn't sustainable beyond that instance. That's why they reset it all. That and the network saying no to continuing it.
See, the premise included a bit about how they could never have any support at all. They'd NEED support to keep the ship running. So they shot themselves in the foot because if they'd sustained the damage from "Year of Hell" they'd never be able to fix it and the show would be over.