" If we all spent more time on projects like this instead of the next
Twitter, or designing new weapons the world would arguably end
up a better place."
Doing something is not always better than doing nothing. As a matter of fact a great many things, perhaps even most, interventions do more harm than good.
I'd recommend starting off reading "White Man's Burden" if you are interested in the topic. For a more fun example, google "one million t-shirts for africa"