The Wraith are reliant on humans for food, but this is complicated by the fact that humans breed very slowly and thus the Wraith spend most of their thousands of years of existence in hibernation.
It turns out that the vast majority of the Wraith population is essentially clone soldiers and their ships have AI which can hold conversations and are not dependent on a steady diet of humans.
Why don't the Wraith use their gestation technology to grow humans or other suitable species, thereby removing their crippling reliance on the free range human population? Why do they waste their limited food supporting all those hungry mouths when it would be more efficient to use the same weird meaty technology they use for everything else?
This wouldn't even change the conflicts all that much, since the Wraith would still be ageless, alien, man-eating, sadistic, imperialist drug-pushers. They'd probably be even worse, since they'd be free to use free-range humans for entertainment rather than food.