Star Trek: Deep Space Nine featured the Dominion War storyline.
The Dominion War storyline from Star Trek: Deep Space Nine is one of the series’ all-time best. It featured a group of aliens from the Gamma Quadrant looking to invade the Alpha Quadrant through the Bajoran wormhole, and trying to conquer the planets and species there. It saw the Romulans, Klingons, and the Federation on the same side for the first time ever, and some of the best battles and episodes Star Trek was ever able to muster.
“In the Pale Moonlight” is better than whatever your favorite thing is.
So it was beyond strange that the Enterprise of all ships was never really mentioned during the show. If it was, it was mentioned in passing and therefore doesn’t qualify as being truly incorporated.
Why does it matter what the Enterprise did during the Dominion War?
Now, why does that matter? Simple, three of the main characters of the series, Captain Benjamin Sisko, Lt. Commander Worf, and Chief Miles O’Brien were all to one degree or another, part of the Enterprise’s history. Sisko’s assignment on Bajor started with Captain Jean-Luc Picard briefing him onboard the Enterprise. Making it beyond awkward, as Sisko long blamed Picard for the death of his wife.
For Worf and O’Brien, they directly served under Picard for years. They had friends on that ship, history, and family. They were integral to the history of the ship and its crew. So it was wildly strange that despite there being scenes where Jadzia Dax and Julian Bashir openly talked about those they knew who died during the war, there was hardly any mention of the Enterprise.
Now, part of that may have been because the Next Generation film franchise was off and running, but they spared people before for Deep Space Nine and Voyager, so why not throw in a Guinan visit? Maybe you can have Data pop in, or have Reginald Barclay pop in for a visit. Granted, Barclay was busy trying to get Voyager home, but still, you’d think the Dominion War would’ve been the perfect opportunity to bring in people from the Enterprise, even if only for a one-episode story, or a cameo, to address what they were up to during the war.
There are some non-canon books that detail what went on, but even if there are books or comics that officially address the question, it’s still not the same as seeing it play out on screen.