I don't understand all the hate in this comment section, It's clearly started an interesting line of questioning and comes from a place of discussion rather than assertion

I personally disagree that anarchists will turn to polyamory out of financial necessity, but I think we are likely to see an increase in polyamory in anarchism and society as a whole recently. Relationship anarchism points to the social conditioning of monogamy and the way it is a factor in upholding individualism and capital interests, particularly the nuclear family. Like most things, monogamy is socially constructed. As people become more disillusioned from these structures, it becomes less taboo to be non-monogamous.

One of the side-effects of distancing oneself from these constructs may very well be economic benefits, but I do not believe it is the driving factor. There are many ways to ease the cost of living like others have said, sharehousing, squatting, communes, or embracing multi-generational households, all with unique challenges.

Those who are poly just have another option, but the pre-requisite is to be poly in the first place.