And yes, this is the same Dominion War that was referenced in the last season of the Picard series.
OTOH, DS9 is the only Star Trek that my wife will willingly watch with me; she finds the others too campy. As another data-point she likes the dominion war arc as much or more than B5, which was her favorite sci-fi series previously.
I might also be slightly biased in favor of cardassian plots and actors, if only for Stewart's acting in Chain of Command.
The dominion and bjoran plots didn't really resonate with me at all, unfortunately.
Even saying that though, I don’t think you can say one is better than the other. I can see why your wife likes them both though.
I know; they were even aired in the same timeslot (IIRC Wednesdays at 7) where I lived, and I had a prior engagement on Wednesday nights and only one VCR, so I had to pick which one to record. I settled on B5.
I didn't watch all of DS9 until it was on Netflix.