My general thoughts. There is in innate hierarchical aspect to child rearing no matter what method is used, as kids don't know jack from shit. Which is the whole purpose of said child rearing. Even if kids had full autonomy to live anywhere and be parented by anyone, the teacher/pupil relationship automatically places one over the other.
I defitely feel that having a secluded family of two parents who raise a child alone is flawed, but it's a fairly modern take on family life, as families used to be more unified, and aunts, uncles, grandparents and even older siblings and cousins could and would step into a nuturing, providing or educational role for non-immediate family. There were obviously issues with these families, such as a baseless with one person as the head, to whom all else were subordinate, corporeal punishment being the norm, and having useless restrictive rules based on a high ranking family member's opinion or tradition, not to mention the family including solely biological relations. Despite all that, the set up makes sense, I think. Each child tends to have two primary providers, but is capable of forming strong bonds with any family member who connects well with them. Every child also recieves support from the family as a whole.
If the biological connection as a requirement were dropped, and spooky rules and baseless authority wiped out, I think it's a good setup.
While the support network of a full community/family certainly assists in raising a kid. Without developing a strong bond with an appropriate adult, the child will grow without any conception of what to aspire to. For example, while my parents are, in my mind, very flawed, I can still see the good in them and that was invaluable
to my development into adulthood. The biological parents need not be enforced, but there's no reason to deny either. Certainly, not every adult is suitable to raise a child, but it would be incredibly difficult to find a child the absolute perfect family to be raised in, as they have no developmental history to draw from. Thus, so long as parents are deemed suitable for child rearing by commune-wide standards (eg not being a reactionary, rapist, mentally inbalanced, etc.) there should be no reason to remove them.
Also, some people think kids should just be able to choose where to live at any time for any reason. I think this is stupid. Kids have kneejerk reactions and attempt to run away from home for the stupidest of reasons. There should be a legitimate way for children to raise issue with their upbringing and request a transfer of residence/guardianship easily, but not at will for any given reason.
tl;dr a network of adults is important to easing the burden of child rearing, but a deep relationship with at least one adult is important to development. Biological connection is no reason to keep a child in an inappropriate home, but there's little reason to separate them either.