Anyone can start investing in any way.
In terms of investment strategy, everyone has the freedom to choose different strategies and invest in any strategy. But for a beginner, I think investing in any strategy will not be a good choice. For a beginner investor, no other strategy may be as suitable and easy as DCA. Because in other strategies (DIP, lump sum investment strategy, etc.), you may have to go through complex calculations or the effect of market volatility will force you to panic and the result of panic may not be positive.
Prudent Money DCA Strategy Investing in a long-term plan means that a beginner does not have to go through complex calculations or the market volatility may not affect him. Because the DCA strategy reduces the price volatility to some extent.
can invest with any source of income.
I am a little confused here. Are you suggesting to invest the necessary source of income as well? Maybe you are confused here yourself. Always prioritize only discretionary money for investment. Ignore any other source of income and invest with discretionary money. Because this is the money that is left after meeting your daily needs, which you may not need.
I think you are getting confused here by what you are saying here, the purpose of investing with discretionary income is because since it's the money left after all expenses has been made, you wouldn't be that troubled if your Bitcoin investment didn't goes as planned, so you saying that you need discretionary income when in the midst of financial crisis is wrong.
Although I don't know if I am right. But I think @Gost ms is somewhat right here. Discretionary money may not be necessary for me today, but in times of danger, no money will be discretionary if you don't have an emergency fund. Discretionary money is only needed if you don't have a backup fund, especially an emergency fund. So we must invest with discretionary money and also keep backup funds ready, especially an emergency fund.