The reason central banks might buy cryptos is to have a supply which can be used to short it for price control purposes. The only other reason would be if they are either overtly or covertly behind the creation of one or more cryptos using them as a way to further consolidate their economic and social control. It is easily conceivable that the central banking cartel does indeed want the public to adopt cryptocurrencies, but their end game will involve cryptos that track and control every human being in a new form of technotronic enslavement. Those who love liberty will love cryptocurrencies which are in no way connected to the banking system.