I have a feeling some cryptos might just be used for transferring funds simple because the transfer fees are cheaper, a lot of people now and just converting to alts and then transferring their funds to other exchanges. Sooner than later transfer times are going to become smaller I hope and fees will become smaller but as for now, when transferring I always convert to an alt first. Saves a ton of money. That's why you will still see a lot of alts survive due to this back and forth movement.