This is my exact sentiment here buddy, selling all at once is like saying that you are no longer interested in making money or you are saying indirectly that you will be dieing tomorrow, so their will be no point having any Bitcoin anywhere, because even Elon musk the richest man in the world now is still investing, because he is still looking to make more money, so why selling off all your investment and start afresh if he is going to start again at all.
It is foolish to sell your entire investment after the investment period ends. Because you have been investing for a long time and you have kept your holdings until your time limit ends. If you sell your holdings after that, then you will have to start investing again and you will have to wait until your time limit ends to sell your holdings. But if you do not sell your entire holdings, you can sell some amount of holdings during your need period which will be able to meet your needs. If you can keep your holdings in this way, then it will be good for you.
Well I don't think it is even that easy to sell all the Bitcoin one have accumulated for years just that like, the only time it can be that easy to sell everything is when that particular investor didn't have a good fraction of Bitcoin is his or her portfolio because if an investor has a good fraction of Bitcoin in there portfolio then selling everything won't be that easy because the investor will calculate how long it took him or her to get to that height.
Moreover, any investor that wants to sell all his or her investment should at least have a good plan of what they will use the money for else it becomes a waste and a reckless decision and even the investor will regret after selling and didn't make good use of the money. So anyone who has plan on what to use the money for, I don't see anything wrong with that so long as they have hold for a long term and they have gotten a good return from it.
Why selling all off once, in as much as you have reached your over accumulating stage, you must have made some good amount of profit, why not spend the profit and continue with still the over accumulating.
If I were you, i will only be spending my over accumulation and profit, then hold on to my capital and still continue accumulating because holding Bitcoin for 4-10 years, you must have achieved x10 of the money you used to buying Bitcoin, therefore getting at the peak/over accumulation of your Bitcoin and selling all at once to start from zero level again is not wise and unhealthy for an investor to practice,if you are so eager to sell reasonable amount of your Bitcoin, you can decide to sell half of your accumulation and not all, because you can still get good profit from it to do what ever other business or plan you have in mind.