As far as I know it's not an ability meant for anything at all. In interviews, Yoshida-san said that jumping would be a purely aesthetic function meant to alleviate the feeling that people were literally tied to the ground. Now, at this point in time, 2.0 was being developed, but it hadn't been announced. I don't see why this status would have changed, but it may have. It may be that the new engine supports the recognition of things moving along the Z-Layers, but who knows if we'll be able to jump from one place to another.
I'm all for the feature just because I really do feel tied to the floor.
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Being tied to the floor ruins my immersion. Jump is the only thing that can save it.
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