I followed the childfree subreddit for a while and was also a member of antinatalist groups on Facebook for years since I identify with ecological antinatalism; the main problem is there are many different reasons to be childfree, not all of them are antinatalist (e.g. some people don't have kids simply because they're hedonists and see children as spoiling their fun) and within antinatalism, at least two separate types of antinatalism exist (philanthropic and misanthropic/ecological) that argue with each other. So typical of a fringe-movement there's infighting, especially vegan antinatalists versus non-vegan antinatalists. The antinatalist Facebook groups really achieve nothing.
I also found it's very hard to 'recruit' or convert new people to being childfree or antinatalist. It's seen as too extreme because society has conditioned people for so long into pro-natalism and having children. Therefore purely for pragmatic reasons while still a committed antinatalist- I tend to support nowadays environmental anti-overpopulation charities such as
Population Matters that aren't saying don't breed, but have small families (1 child preferred, 2 child maximum) over large - and this seems to be working in many countries since total fertility rates are dropping.
