Yanis Varouakis isn't relevant for years.Why should we care about his opinions?
I agree that Bitcoin is very suitable for creating price bubbles and the price volatility of BTC is a big problem for the global adoption of the cryptocurrency.
However,I also think that mass adoption might actually lower the BTC price volatility to a level,in which Bitcoin will be stable enough to be used for retail purchases and paying salaries and it won't be used by investors and speculators for creating big price bubbles.