For those people who bought btc at lower price i believe they already sold atleast 30-50% from their portofolio. I don't believe if there some people who can hold without taste any profit from their investment, atleast 10% from their holding journey.
Just because you do not believe something can happen it does not meant that it does not exist, we know of people that got their bitcoins during the first months of the existence of it and they are still holding those coins, in fact there are many coins that have been considered to be lost only for the coins to move years later, so we know this happens and it is going to continue to happen as those people are not interested in getting fiat for their bitcoin, what they want is to use bitcoin to buy whatever they want without converting to fiat.