Since you are a curious creature, here’s my answer to your question about how we might go forward as men and women. Ethical non-monogamy requires honesty, with self and partners, active on-going communication, connection that also allows for a certain amount of independence, understanding that no one person can meet all of our needs all of the time, etc.
It would no doubt take some time to readjust as a society to a world that wasn’t full of jealousy, co-dependency and control as a part of romantic relationships, but we’ve only been doing it this way for 10 thousand years, a mere drop in the bucket of human history.