Just a loose thought I'd like to share. Would love to hear those who disagree:
Assuming no birth control takes places - the poorest regions have also the highest population growth already and helping them would lead to more of the same, amplifying original problems of those regions creating bottomless well of help.
The global fertility rate has halved in the last 50 years, so I don't think this is as much of a problem as you suggest. Our World in Data attributes the decrease in fertility rates to increasing women's empowerment and decreasing child mortality. https://ourworldindata.org/fertility-rate
As KHorton has alluded to, there is a well-established body of literature which indicates that development leads lower Total Fertility Rates. Examples include the books Common Wealth by Jeffrey Sachs and Factfulness by Hans Rosling et al. The following online resources also explore this:
Thanks for the links. However, it seems that the connection isn't that strong, e.g. from the last article:
"we should not be confident that reducing mortality will always reduce population growth . Methods other than reducing mortality seem more effective in reducing population growth."
and
"the most effective means to achieve decreases in fertility and population growth in Sub-Saharan Africa would be to invest in family planning services and female education."
But except for Sub-Saharan Africa it seems to be working well so I feel kinda convinced :)
High fertility and death rates are normal for illiterate societies, this has been the way we lived for 1000's of years. The way to low fertility and low death rates is via basic education.
Note to the author, and to other readers: If you have loose thoughts you'd like to share, I recommend trying the "Shortform" option, which specifically marks a post as being brief, quickly written, and exploratory.
I'll also note that poverty rates are declining sharply in most of the world's poorest regions, which makes the "bottomless well of help" claim seem a lot weaker.