> If anything, it's a relic of the Abrahamic faiths and their influence over Western cultures.

What? Monogamy was already mandatory in Western culture (meaning classical Greek and Roman culture) before there was any influence from Judaism. And Jewish scripture is explicitly polygamous.

Monogamy in Christianity is obviously the result of the influence of Western culture on Christianity and not the other way around. For Judaism that is not so obvious, since it, unlike Christianity, at least predates Classical Roman culture.

Meanwhile, in the third Abrahamic faith, Islam, monogamy is not even an element of the faith today.