Cryptocurrency is one of the battle of the fittest, the coins with most usage and accepted by everyone will be the one will stay. Some coins are just being redundant and imitating/copying other coins like BTC and ETH. But I think that old coins will be included to be eliminated because we are always having new technology and innovation.

Improvements is always there in every ICO, so there will be new payment method and if the previous coin will become stagnat, they will be also vanish in crypto world.