DCA is a really good way of investing, but it still requires a certain amount of discipline and commitment to the goal, which most people can hardly achieve. The same method also implies long-term investing, which many are not ready for because they do not want to keep their money in something they do not even understand and consider risky.

What you say about the amounts that someone buys is absolutely correct, because buying 1 BTC for $16k and buying it for $24k is definitely a big difference, but buying $100 worth of BTC in the same price range is not exactly something that most people will profit from. Are there still people who think they have to buy 1 BTC? Oh yes, they really exist - because the number 1 for most of them is something just a little higher than zero, and 0.00100000 BTC doesn't look like an attractive amount on the account.