In these incredibly nihilistic worldviews, what is the framework by which a logical case can be made that something like “suffering” is even to be avoided? Who

In these incredibly nihilistic worldviews, what is the framework by which a logical case can be made that something like “suffering” is even to be avoided? Who cares? An individual organism (whatever that even means) may minimize its own suffering, but why should it care about anyone else’s?