What is the need of taking profits overtime? what will you be using the profits to do? those are the questions and projecting 20-30 years will depend on the age of the hodler and if they have also reach their target of accumulation. The only time i can consider to take profits from my investment is after i must have accumulated to my satisfaction and have made a lot of profits which i know that if a take the profits i will invest it on something productive but taking profits and still keep it in Fiats or some stablecoins will make no sense at all so before intending to take profits you should be able to have a concrete plan of what to do with the profits you have gotten from your investments.
Profit is taken either when it's needed or when the target is reached.Other than that - surely, one should hodl more and stay happy doing so.
Talking about the bold words in your statement, honestly it's mostly traders that talks like this, you don't take profit from your holdings because you are in need, that's why source of income and an emergency funds are in place to sorts out your financial needs, your Bitcoin holdings is an asset you hold for a very long period of time in other to change your financial status for ever, not what you just hold and decide to withdraw because it's been needed to sort some financial needs, it's only traders and those that Normally sell their Bitcoin for minimal gains that thinks and speaks that way.
You are actually right but the all bold statement is not totally wrong, the only place that is wrong is when the person said profit is either taken when it is needed, that is totally wrong we are not investing in Bitcoin to take profit when it is needed and whenever you take profit from your wallet because of challenge or whatever it because trading because investment is always for some duration of time which could be 4,5 or 6 years and even more. However, anyone who has this mindset that profit is either taken when needed will never go far in his or her investment because the person will be so much dependent on the investment and you are right when you said it can be taken when the set target is reached but it is not advisable to take all your profit just because you feel you have gotten to the peak, you can decide to take some cent and enjoy yourself and use some for something that will generate more money.
Many people, probably moreso with poor people, tend to be too anxious to take profits and to fail/refuse to let their investment into bitcoin ride. Of course, people have to create their systems and to figure out ways to balance their finances and their psychology so that they do not end up cashing out too much too soon and perhaps for the wrong reasons (even though the reasons might seem right at the time that they cash out too much too soon).