In the line of how this spoiler is saying Kagyua is defeated, if it is the end then yeah I would have gone and said this would have been better if the fight was about 15 to 20 chapters.
Given that Kagyuas fight was short but the highest stakes one, Kagyua wasn't the actual villian, that was whoever was in control at the time like Obito/Madara and otherwise black zetsu. To me, Kagyua is more like just the final hazard, the powerful being who brings ruin in some form type deal but not the insginator. This is common in many older RPGs where you face the villian and then, like I said before with the twist of what black zetsu did to madara, the villian you spent most of the time fighting around the game is beaten in some way by your efforts but then the "ancient evil" or "powerful deity" emerges and is usually the final boss of these games, otherwise the final hazard of the story. Recently that game bravely default did this, you go through the game and when you come to face the insginator, the villian, when you beat them, that person had a master, something that wanted to break free of a prison and attack the heavens, it was much stronger in terms of what it displayed but the fight is not that long.
My point is, any story, the villian isn't always the biggest threat, sometimes there is something more that serves as the hazard, as a result of what the villian brought about.
Kagyua isn't a villian who we had to explore or know, she is a villian that just presented the biggest threat to the heroes and the world itself, viturally almost eliminating all of humankind in the naruto verse. Basically the crisis had happened once in the past and some people fell victim to it, this time it needs to be stopped for good.
As spoilers will say this or that, I won't go believing the stuff till I actually see it, but just on this though, we don't know if something else will occur or if the fight has actually ended. I mean is Madara still around? Will he come back? Could Kagyua possibly go into a berserk ten tails form? Apart from how it was presented, Kagyua was more of just a direct threat, not one for the motives or understanding of it, she was just the highest stakes villian, the result of the plan of the others, the consequence of what Obito and Madara fooled around with for so long, she was beyond their control.