Prominent angel investor, Jason Calacanis, asserts that Ripple's XRP is centralized and controlled by a few individuals.Calacanis believes that Bitcoin will eventually be replaced by a better digital asset, but dismisses XRP as a potential contender.He suggests that it is the right time to 'build a better Bitcoin' due to the dominance of a few large players in the market.Some Bitcoin proponents argue that Bitcoin cannot be replaced and that second layer protocols will determine future competition.