For me the usefulness is more in having a simple strategy, especially if you are an average Joe investor, as most of us are: DCA, HODL and forget about the ups and downs of the market. People who use other strategies are not the kind of people who go around the forums looking for that kind of advice.
This is what I do in investing, it's that simple! I do weekly/monthly DCA and HODL bitcoin for a long period of time. I just think I'm saving without having to look at the current price conditions until my target to accumulate bitcoin is achieved, occasionally I lower the capital if I feel the price is too high and when the price drops that's when I double the capital, I've been doing this for quite a while and I've felt the benefits, what needs to be emphasized is when holding because even though it's easy it turns out to be quite difficult to do.