“the primary attribute of all useful currencies is UNIVERSAL believe or acceptance that they have value”
The coins do have value to their native blockchain, as they are required to utilize the blockchain ecosystem and technology. As its value increases within the blockchain it begins to have a perceived value outside of its blockchain, and can become a valuable asset (which is why I look at them as more of a share of stock or a piece of ownership rather than money).
Yes, today many of these coins are merely for speculation as they have no customers, hence no asset value except for faith and promises. However, value can be perceived by both a buyer and a seller, and if a mutual perception is achieved, the coin can assume the attributes of currency, which in reality is just a tender of exchange.
So yes, these are useful currencies within their ecosystems, and have a value, whether perceived or vested. However there is no such thing as UNIVERSAL belief in any currency.
“However there is no such thing as UNIVERSAL belief in any currency.”
sure there is: the U.S. dollar is practically the world’s currency ...