There is an option of dividing it between "publisher" (source) and "cachers" (caching whatever is recent and popular) but that only helps a little bit.
> Then there is the whole tragedy of commons: average seed ratios and streaming video players for torrent content shows that are not willing to contribute to the greater good.
Over 2 decades of pirating that has only been a problem for obscure and old stuff.
I don't see it being a problem in social network sense; you publish your stuff, if there is nobody wanting to look at it, seeds 1, leeches 0. Moment there is interest it propagates. It is of course problem if you want to see something archival that author is no longer in the network tho.