1. What should we expect from cryptocurrencies on the scale of years or even decades? 2. How many will be there and how many do we actually need?
1. If ICOs won't be regulated within this year or next coming years then we will have a sea of trash icos that doesn't have real usage and all are thinking an exit scam and soon icos will be dead.
2. There will be no exact number as long as the coins are essential and sustainable in the community it will and should remain.
Regarding No. 1 you said, before the ICO was born, many projects had already called for investment and had died, it does not depend on how many ICOs die. But what ICOs will do wonders in this industry