it won't return the investment in terms of increasing Dash's value because these people don't have very much money.
If each person has just a few dollars, even tens of millions of them are fairly insignificant really.
I think you are missing the point to a capitalist economy in general. Its not about serving the richest people in the world who have already made a fortune, it should really be about enabling growth especially in parts of the world where it is currently restricted or underserved for various reasons.
The majority of wealth in the world orbits around politics and military strength. The very poorest people who you discard as insignificant importance have one important characteristic even the largest of companies and wealth cannot challenge which is the potential for growth. The very smallest entities in an economy always represent the fastest possible growth and because there are millions of them this effect can be massive and game changing and justify all of that crypto network allowing them to proceed despite being normally disadvantaged in a world biased to the largest scales of economy
No, YOU'RE missing the point. Capitalism is about managing capital. It's about rewarding the productive and punishing the unproductive.