I think that 95% of crypto coins and tokens won't survive and the reason is that a crypto coin in order to survive and get value it has to be accepted as a way of payment for purchase goods or services.
Very few coins will manage to do it at the end of the day and of course these coins will get enormous value.
The only thing you have to do is to find out which coins will enter the market of real currencies.
You have a rhetorical question. I can say with confidence that 60% of all crypto-coins will be able to realize their final goal, which would be to enter the ICO and only 20% of companies that have Come out on the ICO will be able to make their product permanent. Because at that moment there will be competition, which will very much survive the weak. This is a real story, which will be very soon.
How you can say with very confident? I dont think that very easy to say that percentage above since there are many subject that we need to use to make that confident percentage. However, there are many of altcoin that have no serious team then it will just fail.