The Altcoins have a future, but we still do not know what the future will be like, it can be a good future or a bad future, but, nevertheless, it can depend on who holds them.
I don't want to generalize the future of altcoins, some alt coins are performing well for the past years but most of them aren't.
It's very easy to say that the alt coins has a future but we don't know on how many of them can survive. Some are doing good and remain constant with their performance but others, the longer they have been in the market, they are more to be dumped.