I don't think "deep, meaningful relationships with people online" can truly be effective as a solution until we solve the "endorphins/oxytocin/dopamine deficiency problems". As a species we evolved a ton of inter-related neural pathways that "feed" on inter-personal physical touch as a activator. (Everyone could use at least one 20 second hug a day to light up those pathways.) Loneliness is going to remain a problem, despite well formed and meaningful online relationship groups, so long as people remain touch deficient. It's quite possible we could medicate that visceral, species-wide need away in the near future, but at least for now, physical relationships are always going to have that profligate advantage of primal neural hormone joy that we need to feel less "lonely", even and especially in a crowd of (virtual) friends.