Emotional loneliness is the absence of a close emotional relationship. Those superficial acquaintances that can cure social loneliness won't touch the emotional variety. That explains why people can party for weeks and still feel lonely. Although even one close relationship can cure emotional loneliness for many, that close relationship is much harder to build than a social network. Developing a close relationship can be scary.
All close relationships require self-disclosure.
That frightens many people because of the potential rejection factor. We need to meet a lot of people to find our kindred spirits. Meeting a lot of people requires a lot of effort. And it does not happen quickly. Developing a close relationship also requires a non-competitive atmosphere.