Well, it could sometimes veer towards melodrama.
DOMINION: We are the almighty, invincible, unstoppable Dominion. Marvel at this by-the-numbers pulp sci-fi arc involving the invincible alien foe who are menacing for a long time and then, when we are finally being conclusively beaten by the good guys, inlist the aid of another menacing alien foe, the Breen. created almost out of whole cloth for the occassion. Bwahahahaha!
I didn't think the Dominion were all that interesting until Weyoun showed up and the Cardassians were made members. Odo's relationship to the Founders had its plus points but on the whole his relationship to his Cardassian past was more interesting. Here's some more.
SISKO: Dukat is pure evil. And just in case you, the viewer, don't understand that statement, he will be wearing red eyes and worshipping an evil devil god who I, as an agent of the Prophets, will fight for the good gods and win in a pseudo-religious Manichean battle, ha ha ha ha. Nuance was getting boring.