Cryptocurrency is risky as stocks is also risky but stocks looks more stable and regulated than crypto. Cryptocurrency on the other hand will offer huge returns if everything goes on well.
The bigger the risk means the higher return and cryptos are risky which means it can give good amount of profit if things will happen according to plan. I agree that stocks are more stable but the thing is ROI seems to be not that big. This is the reason why some people tend to buy and sell in cryptos because it can really give them profit within a short period of time.