If you are going to do DCA, you must do it with sense and strategy must be applied to it. You can see that there has been headline that strategy is in unrealized loss of $9B worth of Bitcoin but all that is nothing if he didn't sell Bitcoin at this prices that everyone has been shouting. He has been buying Bitcoin since 2013 and he went full mode as strategy since 2020 with long term vision, this is what many people don't understand about Micheal strategy.
They have not been buying since 2013, but they made their first purchase in August 2020. Where did you learn that they bought in 2013? As far as I know, in 2013 or 2014, the Saylor was not in favor of crypto, he said it is a bubble and won't stay for long and would vanish shortly.
You can check this out anywhere. But I agree with all of the other things you said, I did dca and doing it for a long time but unfortunatel,y, I sold at $90k when it was rising, because that day, I still remember, I thought this is it, it won't go above this price range. But the moment I sold it goes down back to $87k and then goes above, but I was chill because I only sold 50% haha.
Anyway, I still hold some amount from that DCA and also adding more even if it is $10.