Link to this post in three years and ponder in its prescients... Web 3.0 will be born in the death of the heavily botted social networks. Reddit, Facebook & Instagram, Twitter... are all basically pay-to-win schemes at this point, benefiting greatly in terms of adoption from the grey market pay-for-likes botnets, where marketers and propagandists know they can make their content highly visible if they're willing to pay.
People pay very little attention to the fragility that has arisen in the Web 2.0 economy. Once there is widespread understanding of the gaming, cheating, and botting, these social network institutions will crumble. There will be piecemeal attempts to reduce botting, but they will annoy end users, and annoy investors and shareholders as they come to realize XX% of their user base never existed.
Web 3.0 will be the death of anonymity, with social networks and APIs that are, by design, hard to automate, and even harder to hide your true identity from. There will be CAPTCHA-like systems (possibly tied to hardware) that facilitate this. This will of course promise to fix the problem of botting, while heavily benefiting surveillance, for state, and for advertisement. There will be a new breed of social networks built around ensuring the content you are seeing is genuine or "organic", and yet the incentives will be much more perverse, and their networks, much more invasive.