True. But it's still possible to spare some money and spend it on BTC. You just need to establish a budget that will help you keep track of expenses in an effort to reduce unecessary spending as much as possible. Why not start by cutting costs? You can lower your Internet service speeds, cut cable/satellite TV, and even reduce energy consumption. The remaining amount of money can be used to DCA on Bitcoin.
There's literally no excuse not to start taking control of your financial life, and become rich with Bitcoin. But of course, investing is not for everyone. If you feel you can't just do it, then just "stick" with Fiat. Just my two sats.
It's always smart to reduce or minimize your spending cost so that with same income, you can have more money for saving, emergency fund and investment fund. Saving a little bit more money and using it for investment, in one month, several months might not look to be too big and considerable but things will change considerably after several years.
By saving money, investing it in Bitcoin through DCA strategy, after several years, your total money spent for investment will be big, especially with Bitcoin price growth over years, your Bitcoin portfolio will become much bigger in value with time.
I'm not against cutting costs and saving money, but I do not think it is a comprehensive or highly effective solution.
Focusing solely on cutting expenses to the point of making life unnecessarily difficult, while neglecting income growth is the mindset of the poor. That mindset will not lead to any significant financial improvement, even if you invest those small amounts in Bitcoin for many year.
Do not cut expenses to the extreme and live so frugally that it affect your quality of life just to invest. Instead, low income earners should prioritize and focus on increasing their income rather than simply saving for investment. That is what a real long term solution looks like.