With trading, there is the potential to maximize short-term gains, but also the possibility of losing out on long-term gains.
With holding, long-term gains are realized, but we miss out on making further money on the day to day volatility.
Trading versus investing does not need to be mutually exclusive: we can hold a certain portion of our portfolio for the long-term and trade a portion on a daily / weekly basis. Doing a combination of both holding and trading might be wiser than doing either one alone.
Of course trading takes knowledge, time, concentration and energy and when we don't have these skills or the time to trade, holding is an easy way to go.