Portraying volatility as a benefit per se is nonsense, because volatility can also work to your disadvantage. It's true that traders are primarily interested in volatile assets, as they tend to be highly impatient speculators. However, traders are fooling themselves if they think that crypto trading equals making "easy money" - in fact the risk is even higher than with traditional assets. But since traders consistently overestimate their abilities they are unlikely to acknowledge that. Most traders end their activities with a negative return on investment, but will remain silent regarding their failure out of embarrassment
I tend to disagree. There would be no disadvantage in volatility if both assets that you sell and buy are equally valuable to you, for example, Bitcoin and dollar. Price stability, on the contrary, would definitely mean that the value of your portfolio remains the same whichever metric you may choose to gauge it in. In this sense, you don't particularly care which direction the price decides to go as long as it goes somewhere and doesn't stand still.