I think it's not possible to have an accurate prediction like this on long term. It's already hard to predict what will happen to crypto currency market on short term, now imagine how hard it can be on long run. There are several events that will impact the market positively or negatively.
And sometimes there is no way to know what events are these until they happen!

Usually, long term predictions are very positive, their goal is to increase investors confidence and trust on the market, not necessarily to predict a real scenario.