Do not underestimate the lump sum strategy and the buying the dip strategy by saying that the DCA strategy is the only useful method of accumulating Bitcoin for both new and old investor, you are simply saying that other methods of accumulating Bitcoin is useless that is wrong mate all the method of accumulating Bitcoin is useful in one way or another investor chooses to make use of the method that works for him.
The reason why the DCA strategy of accumulating Bitcoin is mainly use by investor is to help them accumulate more Bitcoin little by little regarding of the price weekly or monthly and hold and that doesn't make other methods of accumulating Bitcoin useless because they are also working for other investors.
I don't see any reason to say investing in other methods outside DCA method is useless. Maybe DCA is more popular and convenient than other investment methods, so other methods should not be called useless. Because not all tastes are the same, if you have an alternative method and you are happy and profitable investing in that method, you can use your alternative method. If you think you will get more benefit from DCA than your alternative method then you can adopt DCA method. Or you can buy dips if you feel satisfied. Which method you take is up to you. But our advice is not to use any methods that make you think negatively about Bitcoin. Remember, no matter what method you invest in, all investments have one thing in common, to be successful in investing you must be long-term.
If you want to invest in a simple and convenient method, you can use the DCA method. DCA method is the most simple and reliable among the investment methods. If you can keep DCA for a long time, then you have no chance of loss. That is why the DCA method is a popular method for most people. Other methods have some complications, which are not beneficial for everyone.
That is, the DCA method is just as profitable as other methods if you can use it properly. But you have to be long-term. There is no reason to call other methods useless.