No, they lost. He took away their possessions. Acquired by them in a uncouth way or not. It's not a win-win. And while some of them will indeed be grateful they are still alive, I imagine, the others will still hold a grudge. Those are the bastards that are dangerous for MC. But the real point is, that of the grateful bandits most are going to be thankful only to MC. They will still murder any other passerby. So MC didn't do a good thing, by not removing them, when he had the chance.
Hmmm...Something new on my isekai cheat ability list: The ability to store living things, like people, in a timeless stroageroom/itembox. And I don't want to ask them for their okay. Just "wanting" to be in the itembox and they are gone, frozen in time.