Those who want to hold Bitcoin for the long term must keep a close eye on the crypto market. Whenever you see a dip in Bitcoin price in the crypto market, you will try to buy and hold Bitcoin. But I know that Bitcoin will pump multiple times in the next few years. .Now bin our time and expect to earn multiple times in a few years from now.
Generally the topic of discussion is strictly based on Bitcoin here and not shitcoins that is your use of the term cryptocurrency implies that you are including altcoins in the discussion whereas the topics is talking about long term bitcoin investment. Moreso talking about keeping close eye in the market movement isn't necessary for investors accumulating Bitcoin for long term, those who keep close eye to the market movement are known as the traders who's intention is to sell at any profit added to their investing for short term profit and that is not the topic of discussion because trading is considered to be gambling.
Considering your DCA method serves you better because it reduces the risk tolerance of volatility and market fluctuations nature of Bitcoin.