Honestly, we don't know enough of the day to day happenings on Dominion worlds to be certain of that. Hell, we barely scratched the surface on the day to day happenings of Federation worlds for a decent comparison. We only have how Starfleet essentially behaves as a guide to how people and worlds are treated, which seems to be a damn sight better than the Dominion.
Ironically, dialogue from "TO THE DEATH" actually gives me the best gauge on how the Dominion treats its worlds. Virak'kara tells Dax that very few Jem'Hadar reach 20 years old, and are considered 'honored elders'. Even Klingons, who are a warrior species and look for ways to die gloriously in battle, live MUCH longer than that... even taking into account they have childhoods while the Jem'Hadar are fully grown in a few days. The Dominion clearly have a lot of cloning facilities for creating Jem'Hadar, and Vorta.
Given how effective Jem'Hadar fighters are, why would the Dominion need so many of them? Short of being at war at all times with someone in the Gamma Quadrant, which there was no indication of that, the only other reason I can think of is they are also used in maintaing order on all their worlds. Their space seems fairly large, so that means having a massive army.
So why do the Jem'Hadar have such short life spans? Best answer: they die from quelling rebellions and constantly taking other worlds.
I am curious to see how long a typical Vorta lasts. If Weyoun is any indication, their clones die even more quickly than their Jem'Hadar soldiers.
One other note: if the Dominion worlds are left relatively alone, I would think there would be many more Vorta around to serve as administrators and negotiators.