Yes, it is true. It is very easy to buy. But holding it until you get to the desired price to take profit is what makes it difficult. Not all people have the mental capacity to handle drawdowns and see their funds melt down to negative. They become afraid and instead of holding or buying more, they sell it. Because when you are euphoric it is very easy to buy, when you are fearful, it is very easy to sell your position.  They don't have realistic timelines and expectations. They don't have a plan for when to average down on their position.

Just buying btc and holding it is not a strategy. A strategy consists of managing risk, psychology, and your position. Getting in the move is the easiest.