What’s the point of open relationships

It's just a relationship with a different set of rules and expectations. Also, cheating involves an element of deception that isn't present in open relationships since you know, everyone involved knows and consents to it already. Whereas in cheating it's not just that they slept with someone else outside the primary relationship but that they did it without prior consent and did it in secret. So I'm at a loss for how allowing someone to have multiple partners "Enables cheating" because it isn't cheating if everyone knows what's happening and is OK with it. Consent is key.