I also think more than 90% will die, although, given the fact there are over 2000 altcoins from which a vast number are shitcoins this is only logical since there is no use for shit projects in this space. However, there are still some many good projects that can fundamentally solve real world issues, altcoins will never die off altogether. Just find the right ones and hodl. Being patient with your investments and keeping strong hands is the way to go and will make some substantial profits in the long run.