But people love a spectacle. And heroics. So we just have to figure out how to make mosquito netting seem spectacularly heroic...
Why weren't you asking the Thai military to divert its resources to mosquito netting programs last week?
No the truth is more grim, we will save people until it costs more than we are willing to spend. Over time that threshold has increased with our wealth - but it remains in place as it must. Most people don't consciously think about it and it's upsetting to many.
Advocates of effective altruism argue that the best of us do this, and that if we all did this, it wouldn't take all of our time.
For people who deal with this professionally the quota is defined monetarily. For the average person its an unconscious decision. But in all cases the amount of resources allocated to helping is not defined directly by the demand.
I'm not sure how to determine what "effective altruism" is arguing, but prominent EA advocates like Will MacAskill and Peter Singer are absolutely concerned with increasing the amount of money allocated to helping people. The conclusion of Singer's most famous argument is that we have a moral imperative to donate most of our money to saving the most lives. Even personally, both live modestly and donate most of their income.
The issue is really not as simple as you describe. Of course every life is worth saving, especially the lives of children. However, given a finite set of resources, would you rather save more or fewer children? The amount of money that goes into a long shot at saving a child with terminal cancer in the US would provide clean water and mosquito nets for many children in sub-Saharan Africa.
Am I saying that we should enforce this reallocation of resources? No. But I am saying that it is complicated.
https://en.wikipedia.org/wiki/Effective_altruism