Could someone tell me what will happens to those altcoin which base on eth if eth dies?
Lets assume that it would really die then for sure most ICO's would jumped into another platform seeing that most projects as of now are basing on ETH platform which it does really make big contributions on its development this is why its really hard to believe or presumed that ETH would easily die on this way.If its being supported by most project then for sure it wont die.
Indeed, recently other platforms create ICO cannot compete to ICO projects use Ethereum platform. Particular is Waves - one of completior of Ethereum - does not have any projects success (in short time) after crowdsale (can grow price in short term).
For now no strong competition against Etherium besides on Waves but its still young but do have potential. If you do see most coins are eth-base.We wont know if some coins would able to toe-toe with it because we dont know on whats the future and the possible coins or competition that would happen against ETH. Dying as of now is nearly impossible to happen.Even bitcoin can possible be replaced too and ETH is a strong candidate.