Anecdotally speaking, probably not. I haven’t seen many poly relationships really last, nor have many of my friends (all queer).
I do see the rise of grandparents caring for children as a thing though, as wages continue to stagnate and both parents are forced to work. Intergenerational housing too. Multiple friends buying houses nearby and caring for kids if one parent is fiscally fortunate enough to be stay at home. That sort of thing.