We all know that Crypto is a long term investment but not all. Many people buy memecoins and some other coins with no use case to make money but they listen to influencers and keep holding after making huge profit to later end up at loss. Always remember that these Altcoins cannot continue to go up forever. Selling at profit will surely make you buy more at low price if you believe in the project.
Also, selling is important in most cases because its same as taking profit which is risk management, brings peace of mind and lock you in gains..
Selling at the right time also allow you to diversify your portfolio.
Note : This isn't a financial advice but my own strong opinion according to my experience.
OP I do agree with the perspective to are talking about, but I think most of the people here are the long-term accumulators except for those who are entering new, so for that particular category I don't think selling really matters because in their case the longer run accumulation not the profit booking on the time, even they can adjust their average accumulation by selling and a point and than re-entering the market on lower price, mostly they prefer safe play with DCA.
I'm a person who prefers the strategy adoption according to the market sentiments, I do believe in DCA but I consider myself multi strategies, accumulator a constant accumulation + extra accoridn to the market moves. Taking risks rewards more that's a fact. Adopting the hybrid strategies opens a wider range to play on the field but being specific limits the risk and rewards as well, The DCA is good for the newbies for those who have tasted flavors of the market before their own strategy will work more effectively.
People always say they are "HODLers" until they lose 50% net worth over night.
It will spice up things if you consider the Bitcoin valuation scale rather than the shity fiat money with terrible inflation + unlimited supply and so on...