> AI enables precision influence at unprecedented scale and speed.

IMO this is the most important idea from the paper, not polarization.

Information is control, and every new medium has been revolutionary with regards to its effects on society. Up until now the goal was to transmit bigger and better messages further and faster (size, quality, scale, speed). Through digital media we seem to have reached the limits of size, speed and scale. So the next changes will affect quality, e.g. tailoring the message to its recipient to make it more effective.

This is why in recent years billionaires rushed to acquire media and information companies and why governments are so eager to get a grip on the flow of information.

Recommended reading: Understanding Media by Marshall McLuhan. While it predates digital media, the ideas from this book remain as true as ever.