I think in future it can be the only cash in our world))
All scam will take their own places, big perspective tokens will take the market, it's already in process
I am not sure about all the altcoins there are few which are very famous and these definitely have a future. Though I cannot say anything about how good or bad their future will be but every one of them will have more users with time. For instance, ethereum, monero, waves, litcoin, dogecoin, omise go, neo, ethereum classic all have some potential to survive.
Not everyone is genius, same is the reality with bitcoin as well other digital currencies. Based on the usage that gets associated with the altcoin it gets more into circulation. In the past none thought ethereum will pump high to such a level, but what happened by the starting of the year looked to be a surprise. Hope the same happens with several other altcoins in the future.