The primary reason to buy and hold forever is it is incredibly tricky to time the local tops and local bottoms. Many try, and very very few actually can do that (maybe with a stroke of luck, or through deep technical trading skills).

Nevertheless, Bitcoin tends to move in degrees of magnitude. It could be 58K at one moment and 90K in a couple days. Nobody knows where the fiat price is headed short term, but what we do know is over longer epochs of time (halvings) it tends to move up to higher highs and higher lows. Zoom out and focus on the big picture!