Because an event is in the Bible I would not take it to be prescribed.
Yes there were disasters and there have also been disasters in our day of monogamous marriage.
WW1, WW2, Korea, Vietnam, Iraq, to mention just a few.
Step fathers and step mothers seem to be more common than fathers and mothers and the worst possible nightmare a kid could have would be if his step mother turned out to ne a man.
Ishmael knew who his father was and helped bury him, and both him and Isaac had a woman for a step mother.
So when we start comparing polygamy with the free for all society of today I don`t think it looks so bad.
Three distinct categories. Prescribed, proscribed, forbidden.