So actually running Bitcoin Core in prune mode is only beneficial for you if you want to cut disk usage and if you run out of space on your SSD or something.
You can't help network, your online presence is not counting as a node.
But it still a great functionality nonetheless and I think this is the feature many of us find the most useful.
Do you people even take the time to read about things before claiming stuff? Right on this thread a couple of post above yours there is Gmaxwell himself explaining that you help the network by running a lite node so I don't know what you are talking about. How would it be useful if it still didn't help the network anyway.