Among the stronger pro polamory arguments is that it is merely codifying what modern dating already is with more responsibility and accountability.

The contrarian anti-polyamory argument might be that the lack of accountability was the point of modern dating norms.

The trad arguments aren't relevant either way, no one including the reads themselves believe they will beat out liberal sexual norms.

This is an inter-liberal argument.

I don't think arguments don't decide sexual norms. Too much historical evidence against this position.

For those interested in my thoughts on where society will land:

I expect polamory to win in name, but normative monogamy for the Middle Class will be snuck through the fine print. (As happened with gay rights)

The wealthiest will likely converge on something like Grimes-Elon.