It is a hypothetical question, we don't need to bother what would happen in 100 or 1000 years time. We should only be concerned
what would happen in 10 to 30 years time. I firmly believe there wouldn't be any cryptocurrency in 100 years now on. It would be replaced by
a new and more advanced currency.
I agree with you, there I no purpose of bothering what will happen 100 years from now since all the users of this forum will probably be long dead by then. Even if we think about what's going to happen 10 years from now it's impossible to predict something the way technology is evolving right now.