In most cases the abuse doesn't start early, were elder DC's have been removed the court can have a removal order waiting, you seem to think that every DC is left in the situation and it isn't the case.
Abuse is rare it is mainly neglect, this doesn't always happen to the first DC, it is after a bad pregnancy or PND, for example or a relationship breakes down and depression sets in.
You seem to think that it is claer cut, in the link i posted only one twin was abused, child abuse doesn't make sense and follow a pattern, that is easily picked upon.
The outcome for DC's in care isn't that different and no better for DC's in neglectful situations, we could not find adoptive parents for all of them.
It doesn't always happen at birth, parents lose jobs, start on drink/drugs, the emotional bond was formed when things were fine.
DM gets new BF, BF is the problem.
You seem to supporting any adoptive parents rather than birth families.