24/7 365 "Breaking News" TV - AKA spin factories - complete with scrolling tickers and a combative talking head format (with programs that may or may not have actual trained journalists, but so-called experts at expressing their biased opinions) is the other huge driver.
That's pretty well understood though, right? If love and fear are primary drivers of engagement and fear is a stronger emotion than love then steering viewers to view things that upset them is in the best interest of the company that earns its revenue from keeping them engaged.
the money/power/fame are the drivers, the social media platforms open up the search for those things to a much wider audience while espousing the importance.
that is to say : social media isn't innocent, but it's a co-factor in the larger human-dominating infinite search for power and fame.