I don't agree to your assertion that it's not ideal to take off profits within the bull run like what's the essence of investing? Isn't it to make profits? So in a situation whereby an investor have achieved his major aim of investing which is to make profits so after selling off his bitcoins the next for him to do is to pause investing for sometime until the price begins to dip then he can start buying and holdling again till he aquires a reasonable amount or better still he apply the DCA till the price skyrockets again so that's what an experienced investor does.
In trading, making profits is not guaranteed all the time so accumulating for a very long period like 10 years as you stated may not really be an obtainable idea as the future is unpredictable no one knows how the fate of the coin might turn out due to some uncertainty that surrounds the stock coin market. Making accumulation for a very long period of time might even lead to losses because in the quest of hoping that the price will skyrocket then it suddenly starts dipping so it's really not ideal to accumulate for too long as no one can speculate or predict what it's future holds.
This has never happened in bitcoin history for over 14 years now if I am not mistakenly bitcoin has never seized to changed in price for every year till date so saying that the price of bitcoin might failed one day shows how little your trust and believe for bitcoin is and to me you are also not worth calling a bitcoin because you are preaching the message and mission of bitcoin. As a matter of fact since from inception of bitcoin we have never record any bad price whereby bitcoin keeps failing instead we can say that bitcoin has been repeating its history for over decade now and is sequential whenever the price dip with few months it gets back to the previous price except for bear season where we know that the price doesn't make a change rather it keeps declining to some certain point and takes back it's bull again...
.. there are people who are basically doing trading especially the institutional traders these people trades for individuals and return their profits either by every month ending or by weekly, trading is one the most common place where people makes profits ( it could be a crypto/ forex/ binary trading) they are all reliable way of trading except you aren't a professional trader where you fund and sweep your account. Those who are rooted into trading makes cool cash from it without incuring much lost rather/or crypto trading can be more secure than binary or forex trading.
But know it that gambling can never be equated as trading because gambling is more of probability and chance based game instead of trading, in trading whenever you buy bitcoin at lower price all needed to do for your funds to be is just to hold for while you gain back your hold than gambling. Lemme not deviate from the real subject of this topic but know they aren't the same.