Society types do get their kids taken into care as much as anyone else. As the LA fostering scheme tends to be replaced by a 24hr nanny, relations, boarding schools, summer camps, etc, it doesn’t show as much.
The richer you are, the more you buy your way out of embarrassment.
But private clinics and rehabs don’t hesitate to ring SS if their Old Etonian clients tries to christen his firstborn Arsehole and downs a litre of whisky before ‘parenting’.