You don't have to invest all your earned money to invest. You can invest slowly using the DCA strategy. If you continue your investment for a long time, weekly or monthly, you will see your investment become heavy and you can also prepare for your future now. Yes, you have to do it for the long term because if you invest all your money to invest in Bitcoin, on the one hand, you can sell Bitcoin to meet your sudden danger, on the other hand, you may fail to meet the basic needs of your family. As a result, you can sell Bitcoin, because Bitcoin is cheaper now than in the future. Because when you invest now, it may be your cheap investment because determining the price of Bitcoin is a challenge, but it is possible that anything can happen, such as the price of Bitcoin may increase, but when it happens, you will be disappointed because you gave up your investment because you failed to increase your awareness, so you build an emergency fund to invest, on the other hand, you can use the DCA strategy to meet the basic needs of your family and bring forward your small investment. Do it because it is good and effective for you.
It seems that you don't know the meaning of Dollar Cost Average (DCA). DCA is an investment strategy that gives you the opportunity to buy bitcoin with little amount of money that is your discretionary income consistently and persistently irrespective of the price of bitcoin. It's a strategy used to build your portfolio gradually slow and steady for a very long period of time.
It's not a strategy used to take care of your basic needs. You income should be used to take care of your basic needs and if there's extra cash left, you can use such for your regular DCA on your bitcoin investment.
I'm confused on how he could use the DCA strategy to meet the basic needs of his family. For sure he's confused on the words he used that's why he just said all of those things.
But rather maybe it would be better if he said about that he should use their non discretionary income since this fund should be used on their mandatory expenses or needs.
The discretionary funds is flexible and if they have this funds they can use it to do DCA since by having that they can provably became more consistent in their investment on Bitcoin.