Bitcoin made a huge ATH at that time which was $68k but now the price of Bitcoin is below $38k again so I don't think op investing in Bitcoin now is a late investment. Because there is still time to generate a potential profit by investing in Bitcoin Bitcoin will make ATH again and it should be above $68K. So if you invest now you will get good profit at that time. But yes it is always better to use DCA method to minimize losses. It minimizes losses as well as increases the chances of high profit
I will say here that whether op is late to invest in bitcoin depends on his target or strategy. If op is not taking short time strategy and taking long term strategy then here he is late depending on his current invest and target strategy. If he is thinking about short term trading then I would say he is a bit late at the moment. It is true that Bitcoin has been pumping between 35k and 37k for a while now, but I think another bearish market could be seen ahead. Because Bitcoin halving has not yet started, we may find a little dip in the market during the halving season. But like you, I will also say that without thinking about investing once, break down the amount of investment and follow a DCA method and then invest for long term.