The current assumptions and expectations that society has about monogamy and commitment are insane. The idea that one person should meet all of your social, relationship and sexual needs is insane. Especially for those people who consider being attracted / look at other people / looking at porn to someone else as cheating. Like you don't stop feeling physical attraction or even get crushes if you are committed. You just don't do anything that violate other peoples trust.
The queer communities take on monogamy and commitment that does have any assumptions is really the best method going forward. Not to mention the removal of gender expectations for house work etc. Its exactly like you described it. An on-going discussion about what your commitment means and what is and isn't allowed. It priories the relationship over everything else.