Yes this is true the most of the coins and tokens and also project and ICOs will die . But those project what will survive will be on the top and will give very good profit . It is very hard to find those gems!
I think these gems have long been known and there is nothing to looking for.
I'm not sure about 90%, but nowadays very large number of projects are born already dead, that is, they has no fresh idea and, in fact, are nobody needs.