There is little incentive for someone with significant information, reason, or intuition to reveal it early leaving the market dumb for most of its existence or also open for someone influencing the outcome late.
They also aren't currently that reliable for gauging the wisdom of the crowds for situations where trust in the market effects its outcome. It's easy due to the scale of them for someone to just burn money to skew the perception of it for rhetorical and influential benefits.
I feel like there is no getting off this train though because news media companies are still desperate for revenue. Gambling around news will either increase advertising revenue for them, or if they do real information uncovering journalism, drive subscriptions because there's now incentive for getting news early on more than just financial news.