I don't think all these INDEX work long term, because of the dynamic in the space, they do perform well in a bull market but not in a bear market. I have observe them closely and I have not seen any of them that has actually won me over. With time when the space mature maybe things will be different
We assume that it is chicken and egg problem. No indexing can become sustainable till index instruments appear. And instruments won't appear till indexing strategy on crypto market becomes sustainable. We tend to solve that with Indexing engine.