Oneness is entirely possible, it's one person being secure and happy within their own skin.
If two people are in a relationship, both of them secure and happy within their own skin, then this can be a beautiful thing. Adding any number of people who share the same trait will have a good chance of being a healthy and happy group.
Striving for this romantic idea of becoming one (definition needed) with another person is a use of energy in direct conflict with what I see as reasonable.
Me: male, 40, straight, single