Greetings...
Can a satisfying adventure be designed where one doesn't require there to be a climatic confrontation? Well, I guess you could. But I don't see the point.
The key to any good story is that there is an arc. An introduction, some character and/or story development, the introduction of the conflict and it’s resolution. If I remember correctly from my study of literature, there are three types of conflict. Man against man, man against nature, and man against himself. That without conflict it is not a story, it’s just boring prose. Without the resolution of the conflict, then the story isn’t resolved, and there isn’t a proper arc. Without a proper story arc, it’s not a satisfying resolution.
If the players resolve the situation violently, or non-violently is up to them (to at least attempt) and the GM (to allow). But unless there is something done by the GM to rise the tension in the game, and not really resolve things. A good example of this would be the ending of Star Wars, The Empire Strikes Back. -- Sure, the 'heroes' resolved some things, but they weren't able to defeat the BBEGs.
Given the situation that the party has faced a particular number of challenges all with a common thread, theme or source, that allows the party to tie and associate them all together. Having that party 'win' in such a way that there isn't a climatic resolution for them to be involved with, I would think would be a very hollow victory. It's one thing to be defeated, where the heroes have a chance to redeem themselves and come back for more. It's another to have won with little or no challenge.
Let us say that they party had found out that a secret cabal of magi were behind a plot to destroy the church and the crown by orchestrating situations that convince each other of duplicity and malice, using a thieves guild to execute their schemes; and that the party is thrust into the middle of the situation.
Upon learning the truth of the situation and the party tackles the problems and resolves them. These series of adventures are reward in themselves. But one would think that the party would be concerned as to who is behind the plot. They may first find out that it’s members of the thieves guild who are involved. They may even be brilliant enough to find out it’s actually the true masters of the conspiracy, the cabal of magi. Now, let’s say that the party isn't powerful enough to take on the magi, or even the thieves, and understands this fact. They have two choices. Hopefully, a smart party will realize that they should only confront their enemies when they are powerful enough to do so.
But, when it comes time to deal with their ultimate enemies here, the cabal of magi, after all of their schemes have been thwarted, and the party realizes that they aren’t powerful enough to take on the magi head-on. Perhaps the church and the crown deal with their true enemy themselves, and the party isn't involved at all. Or that no one is powerful enough to take on the magi at all. If that is the case, and there is no resolution. Without any resolution, it wouldn’t be satisfying for anyone involved.
However, if there was a solution. Let’s say that the church and the crown teamed up, sent out their elite forces, and smashed the cabal of magi. With the players pretty much standing around doing nothing. Not even involved. -- I wouldn't think that the party would be satisfied with the resolution. They may understand it, and accept the resolution. But I don't think anyone would get any pleasure or satisfaction from it, because they weren't involved in the final solution.
Thing is, behind every problem, there is conflict. Without conflict, you don’t have an interesting story. If the players aren’t involved in the resolution of the conflict, they are just spectators.
There doesn't have to be a BBEG, or the apocolypse... again! But there does need to be some sort of method or way to allow the PCs to be involved in the resolution of the conflict.
Does it really matter? I would have to say yes.