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.