Most of the existing altcoins will die after a few years. Only those who have a new technological solution, an experienced team of developers and a community of people will remain. Now it looks very interesting EOS.
Yes, you maybe right, almost every month new ALT coins are posted on the market after the ICO, some just disappeared after the few month on the market, for simple reason, no investors invested for the said ALT coin, support system where not stable for long term in the market, market structure were not clear, fundamentals were not stable, this are some consideration for the possible ALT coin to look into. The ALT coin whom had a good potential for the future is Ethereum..