If you don't see character arcs in Ro, Kira/Keva, Sisko, Odo, Bashir, Dax, and Quark -- amongst others -- then you weren't paying attention.
^ Some of them may have had a story arc through it, but known of them particularly developed, every single one of those you mentioned, including Quark, have acted like they did in this story for many many years.
The only thing that seemed to develop over the course of the story was the new station.
This is precisely what I mean. Yes, there is "screen time" for all of these characters, but they don't do anything. Their stories don't advance the characterizations. They don't advance the universe. There were a couple of events that were biggies, obviously. But the characters could have been swapped with any old redshirt, and just as much would have happened.
Now, I know some will say, but what about all that introspection that these characters did? The problem is, even the introspection was a rehash that failed to build up to anything.
I really don't know how you can say there was no advancement to the characters when it's very clear that, for instance, Ro has an entire arc about what the constant catastrophes on DS9 are doing to her state of mind; how Sisko is re-adjusting to family life and to the possibility that his daughter may have some role to play in future situations with the Prophets; how Odo is coping with the loss of the only two things he evert really loved, Kira and the link; how Bashir and Dax are finally moving on from the pain they caused one-another; how Bacco was fighting to overcome her grief at Esperanza's death and yet continue the work of peace-building; how Quark is continuing to adjust to his relationship with Ro; and of course how Kira is learning about her new role from the Prophets.
Now, maybe you don't think there's enough payoff there. My rebuttal to that argument is, "That's what they said when
Rough Beasts of Empire came out. It all paid off amazingly in
Plagues of Night/Raise the Dawn."
But to say there was neither new introspection, nor character advancement, or to say that it could have been any old redshirt, is just false.