I have to disagree here.I thought it was a decent way to express the DS9 producers went too far in making their epic war tale as equivalent to the Borg Invasion which spawned the legendary Wolf 359 on TNG. Voyager treated the DS9 dilemma, with the Dominion, how it should have been which was "A Bottled Conflict" within the realm of its own series. Still today I feel the Dominion stories were overrated and the conclusions for each arch were unsatisfying in particular "Sacrifice of Angels" where Sisko throws the get of jail free card and wish the Dominion away, and "What you leave Behind" where Odo simply mind robs Head Dominion Lady to stop hating solids and ending the war. Keeping this war crap for a season or two would avoid too much bleeding through plots into a movie from TNG or the sister series like Voyager.
TNG is the grand daddy of that world of Star Trek and his spinoff series should follow suit, trickling down whatever remnants remain. DS9 never had such a following where a prolong war drama would or could influence the rest. The other productions just didn't care about what DS9 was doing and would not give it weight - the Dominion - which never deserved such grandeur.
I think that The Dominion were great as enemies, much more convincing than the Borg. The Female Changeling was the worst enemy in the whole Star Trek (with "worst" I don't mean bad but dangerous) and her genocidial tendencies really made me hate her. One of the dissapointments for me was that she wasn't killed off so she did make an impression on me, something the Borg Queen never did, neither in TNG, nor in Voyager.
OK, the war did drag on for a long time in the series which cvontributed a lot to the "dark" rumor which DS9 has. But DS9 never became dystopic in the same way as "Destiny" and "Picard" are. There were lighter episodes here and there which did raise the spirit for us viewers.
I also have to disagree with the comment that the spin-offs should be like TNG. Basically maybe but not totally because in that case the spinoffs would only become bleak copies of the original series.
Here we can compare Star trek with NCIS. The original series is the flagship, NCIS LA is somewhat different, just like DS9 was to TNG and NCIS New Orleans is more like the original, a little bit like Voyager was to TNG.
Unfortunately there is another similarity which is not so fun. NCIS New Orleans started good but a series of changes among the cast has ruined the series for me, just like Voyager was ruined by a similar event. So I've stopped watching NCIS New Orleans. Sometimes history repeats itself.