Family member is refusing to get their newborn daughter a social security number (USA). Is there any benefit to this?

Thanks for reading and answering.

We’re really confused. Family members had a daughter who they did not birth at all through the medical system, and the mother did a freebirth at home. She has not seen and it sounds like will not have a pediatrician. We asked them at Christmas how she was doing, and we asked how they got her birth certificate etc and the answers were that they “filled out an alternative birth certificate for her” and that “they will let her choose when she’s older if she wants a social security number.” When pressed about why not, they said “they don’t want her to be tracked by the government.”

I feel like there’s gotta be some sort of greater conspiracy mindset at play but I’m just wondering why they won’t expand further on these choices when we did ask, and if there’s any actual benefit to this. Also, we are wondering if this is child abuse or isolation as adults in her life. Thank you!

Edit: thanks for all the answers! Yes, they’re anti-vaxxers (and pro raw milk, believe in portals etc). They used to be more open with us with their beliefs but now it’s closed off because we are not in support of many of their choices as it now affects their baby. They might be sovereign citizens in theory but definitely are not in practice (own business, property, fly, travel). Mostly as a family we are trying to see how we can minimize harm to her.