Then we all agree that replicator has limitation.
According to "Yesterday Enterprise" in TNG, the warship version of Galaxy Class uses ration instead of replicator just because the energy of the ship is being used to empower weapons and shields.
So..., blockade still work in this "Star Trek World". A colony that being siege by Dominion would suffer starvation. Because with the limitation of the replicator, they shouldn't be able to replace immediately "The planetary power supply" if they are all being bombed and destroyed by Dominion Fleet. Plus with the war, they would use the energy to empower the phaser and shield rather than replicator, thus the people would relied on food ration instead.
So... my conclusion is still the same. It is either plot hole or the Dominion War is actually not as big as we think.
Well, I understand that I'm being stubborn. I know that you all have give your opinion and I'm very grateful for that. And telling a stubborn man like me will exhausted your energy into nothing. So I'm apology for that.