Online mediums that do one-on-one conversations (instant messaging, etc) or small group chats of people who know each other don't have this issue, but they're also pretty limiting for meeting new people. It seems like there's a trade-off between a platform making it easy to discover new people versus a platform fostering conversations between invested people participating equally. The largest social platforms have been the ones that are better on the discover-new-people side while doing worse on the other side.