I think you confused a few points. You mention both men getting apartments so they can form families with their already existing relationships and men who don't have relationships turning to online resources to try to understand how to have them. These seem distinct phenomena. Especially since in many other cultures newly wed couples would live with one set of parents in a multi-generational household. This means while it would go contrary to current social expectations and there would be some stress from doing such, not having an independent home for a relationship should be considered separate from not having a relationship. The latter is what mimics polygamous societies, and if the theory about the disability they cause those societies is true, should give us cause for concern in our own.

That there is a correlation between the availability of housing and effects you mention might be driven by a third hidden factor.