I typically don't understand why people start a relationship in the first place when they don't want to date someone exclusively, how we view relationships is mainly culturally influenced and people don't easily unlearn what they expect from a romantic relationship, even if they think so, a lot of things are unconscious (Jealousy etc). You don't need to be in a relationship. I think especially with younger people and people that have a specific environment where this is encouraged, it's rather questionable for a lot of reasons. I also think that this is feasible for some people, if they are aware of all the consequences and can take responsibility.