Most societies recorded by anthropologists are polygynous. (Around 85% by one count.) The few monogamous ones are almost all found in harsh environments. Once agriculture arose, almost all farming societies were polygynous as well as almost all complex societies or civilizations – with one big exception: the West. Europe was peculiar from antiquity onward. Ancient Greece was monogamous, so was Rome, and the Christian middle ages.
Did this make any difference to the history of Western civilization? I think it did.
For one thing, monogamy means more marital equality among men. This probably has an elective affinity with political liberty and democracy. More equality in marital resources seems to go along more equality in politics. European rulers, however despotic they may have been, could not accumulate vast harems.
Also, monogamy means less competition among men to secure more wives. Men can devote less time and effort to getting wives and more to other activities. Unrelated men can cooperate together.
Plus, monogamy probably induces men to devote more paternal investment to their children.
Some argue that the West, or Western civilization, is not a coherent thing, that it has no distinctive identity. Well, monogamy is one thing that is both distinctively Western and which stretches back over more than two millennia.
Consider Western monogamy a long social experiment. Was it a success? It has been adopted far and wide so that betokens major success.