It is not recommended newbi invest the entire all in fund and maybe this applies to old people as well. Because in trading there is management that you have to do as you wrote. DCA may be done by an old trader who has a good understanding of trading, while Newbi may learn to manage funds is a good start. Start with a small fund and learn how to manage your funds so that they grow and don't run out. Newbi doesn't have to think profitably, focus on learning. That's the best moment where you will be more successful in the next.
However, beginners who are too eager for quick profits will trade without thinking about anything whether it is DCA or other strategies. they will only buy when the hype occurs and will sell when the crash occurs, they panic so there will be no profit. Starting to learn from small capital will be very helpful and not only about profits at first but how you can learn how to manage funds, risk management and learn how market conditions work and see how trading tools work.