but men were OK with the constraints if they are getting a wife,

And they are allowed to rape/sexual enslave non-muslims. This is needed in polygamy as the sex ratios don't work without stealing outside women. This is also part of the reason Muslim immigrants rape so much in the Europe, they are permitted to by the law they acknowledge.

women were OK with the constraints as long as they were safe and provided for.

Women have no say. Islam keeps itself in a constant state of violence, they have no option other than to seek male protection from within the system the men have created. With polygamy there will always be disenfranchised mateless men intra-tribe who will rape men's wives opportunistically given the chance. This makes mate guarding required where women are essentially confined to their homes, and must always cover themselves completely and be escorted by a male family member around unknown men.

But now neither party is getting their end of the deal, and men are taking whats theirs in a state of raw nature.

This is Islam's defacto state, it has always been characterized by instability punctuated by brief stability under the ocassional secuar caliphate or dictator. Polygamy itself guarantees a state of intense male violence.

Look at all the women flocking to ISIS under the idea that they will get a warrior husband and a safe future.

You're an idiot, you mean the handful of women who are inconsequential and only interesting as clickbait for journalism? If you think there's an actual trend of women leaving the West to become ISIS brides, you are a fucking retard bro. The actual trend is women running from ISIS, seeking refugee status in the West.