Buying Bitcoin with a lump sum will allow you to complete the quantity of Bitcoin you want on time, while DCA will delay your accumulation process, in the end, you will still accumulate the quantity of Bitcoin you want.
Part of the problem, is that you do not necessarily know if you will still be able to accumulate as much BTC under each of the strategies. Sure you might end up investing the same amount of money, but you might not be able to accumulate the same amount of BTC, so frequently, each of us has to decide within the means that we have available, and sometimes we might not even have lump sum available to us, absent having to take out a loan or otherwise put our finances in stress in order to accomplish lump sum... but it still does not mean that lump sum is a bad idea even if carrying out lump sum might end up in certain kinds of tradeoffs, such as financial/psychological stress or even potentially not having as much cash available to buy on dips if dips were to occur after the date of the lump sum injection(s).
You are right @JJG. The person who invested in Bitcoin with a lump sum might end up accumulating less Bitcoin Bitcoin because he/she invested in Bitcoin at once and if there is a Bitcoin dip, the person will not have any other money to buy the Bitcoin dip. It is always good to come to this thread to be guided on the best ways to invest in Bitcoin and hold.
I had to quote you, just to fix your quote.. because I was not sure from which post you were getting my quote...
As far as my further substantive response, I am not even saying that there is any "best way" to invest in terms of whether you end up being more profitable or less profitable, and even though we frequently like to measure our "level of success" based on how much profits we make, there likely is way more to "success" than mere profit levels, even though maybe I am also somewhat presuming that if you tailor your own investment approach in accordance with your own personal circumstances, then you are likely going to have more profits from that overall, even if it might not have ended up as the most profitable play.
In other words, we can look back and see that we could have done x, y or z, and we could have been more profitable, but merely being able to see an alternative course that would have ended up being more profitable, at the time, that we make our decisions about what to do and how to employ our capital, we don't know the future, so hopefully, we are attempting to protect ourselves from a variety of possible scenarios both to the upside and to the downside.