Currently, after going through the halving period, everyone is waiting to see what will happen with Bitcoin. I agree with you that investing in Bitcoin can be done at any time, but it would be better if the price is corrected so that you can get a cheap price and immediately hold it. And now everyone will wait for the correction to be able to buy and hold until the market increases, so they can get maximum value.
I do not agree with the remark that "Investment in Bitcoin can be done at any time," This is one of the misleading heresies surrounding Bitcoin investment. We should be smart in our investment regardless of whether or not it's that of Bitcoin, investment is investment and assets are assets. They have good, bad and ugly times, so we should rather wake up and face the reality and not let anything blind us about Bitcoin investments.
Those who bought Bitcoin at a high level in the last bull run are still lamenting, though it tried to impress them better now, but for how long? What if the person needed the money in 2022 but trusted in Bitcoin, can such a remark be good in his hearing anymore? I am an investor in Bitcoin as well, but I invest sensibly. I only buy low and sell high when the monthly chart tells me to do it having confirmed a long-term bearishness on that chart. This is smartness and not just being blinded by some general saying about the coin that looks too perfect.
All those remarks are basically to put the dollar cost average method into the picture. I totally see a sense in what you've said. The idea of buying when dip is totally a common sense as everyone would undoubtedly like to make profits in a long run. Buying when dip would certainly show good signs of healthy profits in the future.
Though, I see no fault in using the DCA method to buy at any point in time, but this could only make any sense if the source of income in using the DCA keeps coming. Because you don't expect me to save up and buy when Bitcoin is around $73K. But assuming I have a continuous stream of income, then I can buy when it's around $73K, $60K, $57K, etc. Though it won't show any sign of unhealthy profits in the future unlike when I choose to buy when dip.