1. Nobody listens to anything Zuckerberg says.
2. Regulate social media platforms with >1M users. Require that they support federation through open standards with published, open-source reference implementations of all required software.
3. Enact EU-style privacy protections, with the explicit goal of destroying the tracking/surveillance industry, both on the net and off.
4. Require that service providers, regardless of size(1), keep hate speech off their platforms. This includes calls for the establishment of ethnostates and other speech that stops short of literal calls for genocide but that has an obvious, well-established trajectory in that direction.
(1) This may not be entirely practical, but it's a place to start. Also, the definition of "service provider" may be tricky to establish.