I get what you are saying. The storage of large files is certainly an issue because it is so expensive to serve them up making it extremely tough to take on YouTube or Facebook at this point.
Personally I feel like another way it has been unsustainable is that the distribution was so messed up from the beginning that now a lot of us are mainly relying on delegated power to DTube, DLive, Busy, and eSteem. It is actually hard to earn real votes that are worth anything at this point. If feels a little bit like it did in 2016 where it is all about hope that a whale will maybe upvote you.