It’s more just sharing things like birth control technology and education.
This whole discussion is actually a sort of win-win scenario, because what proves to lower birth rates more effectively than anything is improved regional health, education, and wealth, so helping along those factors is the biggest impact.
https://www.newyorker.com/news/a-reporter-at-large/china-xin...
"But haven't you considered that forcing people not to reproduce is horrible?"
"Who said anything about forcing? I'm not advocating for forcing anyone?"
"Hah! But in fact people are being forced!"
"Well yeah, lots of bad things are happening. That doesn't have a whole lot to do with available birth control and high income."
"No TRUE Scotsman!"