Because the DCA strategy reduces the price volatility to some extent.
Even if one makes use of DCA Strategy the price of Bitcoin will still keep going up and down after you buy. So I would say this-]DCA Strategy doesn't "stop" rather does it even "reduce" volatility.
What we can say that DCA Strategy does is that it helps spread your buys so you don’t risk putting all your money in at the worst timeNo, I disagree on this your highlighted statement here buddy, the very purpose of dca accumulating strategy is to make accumulation of Bitcoin very easy and affordable even for the poor, because you can be buying it bit by bit according to your financial strength, and point of correction, their is no worst time to buy Bitcoin, because it's still very cheap when compared to how much the value can rise up to in the future, so what you said in the highlighted words are false.
Additionally, volatility is part of the nature of Bitcoin, so it wouldn't go away all of a sudden because you are accumulating through the dca strategy.
It seems you dont understand what he meant, rather you are only defining DCA for us here. Let me take the time to point out his points. DCA doesn't stops volatility, you are only on an advantage to buy whatever the price is atm.
Also, your right. There is nothing like a worst time to buy Bitcoin when you are practicing DCA. Only those who are timing the market (traders) are allowed to use that statement. As a weekly investor what you should be concerned is to work on increasing your income so that you can have more discretionary income to invest with. The price shouldn't bother at all.