I think it's impossible to predict exact numbers like that. It's just funny to do this.
I think "researches" like this don't take into account human aspect/psychology and big events that are hard or almost impossible to predict. I. e. If the economic crisis would come and FIAT foundations would be doubted, we finally have working alternatives. And if people would recognize crypto currencies as an alternative for spending and also saving this can make a huge upward move in adoption (which also reflects in price). I can't think of any other asset/number which could also work for everyday use in today world.
On the other hand people could also be convinced that crypto is scam, shit, not working at all etc. but I think this can't happen on long term because of the strong supporters of crypto - who will never stop trusting blockchain (because they actually knows how it works). The only thing that could really threaten trust in blockchain is bug, programming failure.

Yes.
Only god knows/time will show.