Overlap with overpopulation, abortion rights and antinatalist communities?

[Allen]

Why is there so little overlap between childfree communities and overpopulation, reproductive rights and especially antinatalist communities. I came here expecting these communities to be nearly interchangeable and have something like 80% cross membership, though I knew the reproductive rights community was bigger than the others, but I usually find myself the only participant in all 4 and now think cross participation is closer to 5% than the 80% I expected. Why are we so siloed?
I do realize the demands for increased childcare funding coming from the Reproductive rights community specifically to distance themselves from us under the "reproductive justice" label is a big problem. Planned Parenthood Columbia Willamette even refused to help me include them in my will citing "reproductive justice" despite their hypocrisy in not funding much childcare themselves (though I'm glad they don't). But I find the lack of triple membership among childfree, overpopulation and antinatalist communities very puzzling, though as I have written, I don't identify as childfree as long as the parental majority have us in chains in every town and school district, preferring voluntarily childless.
School boards don't answer to parents, they answer to voters, including us.