I was reading a book on social life of the upper-middle class and new rich of the American 1920s and realized so many things we now do proudly were considered socially taboo back then. This was especially the case for clothing, makeup, women in certain public spaces, etc. What do you think will be different in the 2120s? Or maybe even the next 50 years?
Polyamory goes in multiple directions though. You are thinking of “polygamy” but there is also polyandry and other configurations.
I agree with this answer, too. I don’t really care how many people are in a family together. Live your life.