Most of social platforms are nothing but feature AOL back in the day. They got a different look and feel. Some are cross over of ICQ and AOL (WhatsApp) AOL messenger Chat rooms (discord, telegram) Twitter is nothing but public chat room.
1. Recommendation engines, and other clever ways to drive up engagements.
2. Marketing. AOL's marketing was generally ahead of other tech companies at the time. Modern platforms have marketing on par with any other consumer brand. They are specifically great at FOMO, user acquisition, and feeling like a basic utility for modern life.
3. Network effect. Meta reports almost 3B monthly active users. What did AOL max out at? 20M?