I usually agree with this but at some point I have come to realise how much important investments is to me as a young man hence making investment seems to come first before another thing perhaps I would have to allocate a good percentage of my income into investment and whatever remains I would use to pay for my expenses however my personal expenses are not yet bigger than I can afford and I also still receive stipends from parents hence I seems to have come to the conclusion that discretionary income will only come to play when you have gotten a certain level of responsibility. Just my opinion.
Depending on your income, you can easily continue investing in the DCA investment method if you want. Investment is very important for you as a young person. Now is the time to earn money by working hard and how to convert this money into more money but you have to do it yourself. Maybe most of the youths think they have enough energy in their body now so they can work hard and they are satisfied with the amount of money they earn but they don't think about investment. Because of not thinking about investment, many times it is seen that many people lose their job or cannot work because of some problems, but their life becomes very difficult, but for those who think about investment in advance, this investment stands as a support later.
The first thing you said is that you need to find a big source of income before investing. In this case, I would like to tell you that you should continue investing with a portion of your current income (however minimal it may be).
When you realize that your income has already increased, you can gradually increase your investment amount based on your income. That is, if you are in investment, there will be a tension in your head that you have to earn money and you have to invest consistently.
So, from now on, give utmost importance to the matter of investing in Bitcoin. I hope that this investment will give you many good things in the future.