What contributions has the introduction of cryptocurrency made to the world economy. Many countries mostly in the African region has banned activities involving cryptocurrency while some have legalized it's use.

What effects has Bitcoin or other digital coins caused that have made these international bodies to take the various decisions they have made. Is it that it has posed a great threat to the economic system of some other countries and in the same time help lifted the operations of the others?

What do you think is the major issue or reason here?