DCA is actually good but I think you shouldn't forget the downside of it.
It could be DCA may result in higher cumulative transaction costs over time compared to a big sum investment in a time.
This is really good for a long-term accumulation of Bitcoin, DCA can be an effective way to accumulate Bitcoin over several years. But if you think in a short period of time, forget the DCA option. Because when we say a low-income earner, it should be always a priority in our daily/necessary needs, and only invest what we can afford.
It shouldn't matter, DCA brings convenience, I am sure people will choose the easy way of buying Bitcoin over the gradual pile-up of the transaction fee.
People like Michael Saylor will buy Bitcoin in one go because they have the money, even if the trasnction fee will be extremely high they won't care, but for someone who is trying to DCA, you shouldn't care either because the amount you plan to buy is small, unless the transaction fee is very high at the time.
The rich will buy 1 BTC with no problem, when the market dips they will just buy again, and people like us can only buy $50 worth of Bitcoin per week or month, because this is what we can afford, the transaction fee isn't even close to $1, in a whole year it is $12 if done every month, even if it is every week I believe it is worth it.