Volatile markets are associated with high volumes of trading, which may cause delays in execution. These high volumes may also cause executions to occur at prices that are significantly different from the market price. Volatility is good for traders because it gives them opportunities. Even though the price of the underlying stock may fall, you're still earning steady dividend income.
If market situation is stagnant, it will be difficult for Traders to get profit, I can't imagine how traders can make profit if the Crypto market is not Volatile. Volatile Crypto prices is a moment for traders to get profits. If Traders want to trade with coins that are not volatile, of course they will choose stable coins.