It’s not entirely true. Bitcoin price is volatile so you can have profit as quickly as 1 day or shorter if you manage to purchase Bitcoin right before the price rally started.
It’s not necessarily true that you will only have profit on Bitcoin when holding long term while in fact Bitcoin price pump happened in spread time frame which means you can gain profit regardless how long or short you hold.
What you are saying is not true except that you have a trusted portfolio to give you the kind of profit you are saying on those rally, what they said about only getting profit in a long time is true, let me explain from the angle of those people who are using DCA on bitcoin, so actually there are people whom there monthly entry on bitcoin is not up to $30 so actually even a 12 months is still nothing to give the person the kind of profit that would make them see that they have benefited on Bitcoin so actually is only when the person continue to hold will you see them having some profits, so yes long term holding is the answer.