I can see a lot of praise of DCA here. I agree that it has its advantages: it's simple, affordable, it makes investing into Bitcoin a routine task, and overall it allows accumulating more and more BTC. However, I'd say that if someone has low income and can barely make ends meet, there's probably no good way to invest in Bitcoin. Because I firmly believe that people should only invest what they can afford to lose. Also, DCA is good overall primarily because Bitcoin tends to have long bear markets, so it means that a person is mainly accumulating BTC at a low price (compared to ATH). But we don't know if that's going to be the case in the future, and if the price remains stably high or is even growing, maybe DCA isn't very good because one's now getting a good price for it.
The option to invest is for people who can save some part of their income. There is no need to consider saving if all you earn is what you need to survive. However, one can still increase his earnings by acquiring skills that can make him earn higher or seek other means of getting extra income.
It is predicted that the price of Bitcoin will keep increasing in the future but it will always be affordable since one can buy in bits. Even if the price gets to $100k in the future, an investor can still decide to buy a unit that he can afford using DCA.