I think part of the problem is people are talking about unfinished business and tying up loose ends and all that stuff that would take more than a dozen chapters or whatever, which I'd totally get, except you're forgetting Kishi is the author. You have to remember all the plot holes and asspulls and pure bullshit from Kishimoto. Once you recognize how atrocious of a writer he is, the manga's ending in the next dozen or so chapters isn't farfetched at all.