as i said before, having only one need out of a relationship doesn't make it a relationship. the relationship ends the moment you leave permanently and enter that ldr phase. at that point, its not a healthy relationship as a psychologist would define it as. its just limbo between friendship and intimate emotions, and it will gradually descend into friendship and later into acquaintances. some people like that more than others, and there's no problem with that, but its not a relationship
just like you cant consider friends with benefits as a relationship, you can't consider permanent ldr a relationship. it just lacks the needs that a healthy relationship requires to be sustainable