Relationship Anarchy sorta explained
You asked, so I shall do my best to explain. Let's keep in mind that I quite literally learned about the existence of relationship anarchy a day ago so take all of this with a massive grain of salt lol but here we go:
Western society has lots of rules of how each relationship is supposed to look/operate.
Friends aren't supposed to raise kids together, merge finances, etc. That's only for married couples.
People who are romantically intertwined are supposed to kiss, have sex, etc. and eventually end up married.
The ideal romantic partner is someone who can fulfill most if not all of your emotional, physical, and sexual needs, and anything less is a sign of incompatibility.
There's also the relationship hierarchy that society upholds—or the "relationship escalator."
At the bottom is friends, then romantic partners, then spouse.
The more intimate you become with a friend, the more likely people are to assume you want to be romantic with them—i.e they assume you're moving up the escalator.
The more intimate you become with a romantic partner, the more likely you are to get questions about when you're going to "take the next step" and get married.
Lots of rules, lots of expectations. And relationship anarchy (RA) basically says "no 💙"
RA basically refers to a deliberate rejection of these social norms. No rules and no inherent hierarchy.
Instead, partners decide amongst themselves what they want their relationships to look like.
Here's a nifty graph to help visualize this:
You can be friends who rely on each other as primary sources of emotional and sexual fulfillment. Life partners, but you don't have sex or romance at all.
You can be sexually, romantically, emotionally fulfilled by one person but still just be two people loving and experiencing each other with no need for labels or the expectation of any "escalator" progression towards marriage or anything else.
Essentially, you build relationships buffet style, and each relationship is as significant in your life as you want it to be and they all serve whatever role you want them to serve. These relationships can be monogamous or polyamorous or anything in between.