What's best for the kids seems subjective, to me. Where one kid thrives, another might drown...

I don't know if it is subjective. "Hypothetically", if we could know what child A needs and what child B needs, we could act with precise sensitivity for what is best for each. Of course, knowing what each needs is the challenge so we are forced to act with some kind of probabilistic line of best fit (at best) but we are still going to fail the children a lot as what we consider the "best" is not necessarily in their best interest, but ours.