This assumes an equitable distribution of purchasing power among market participants, so the only barrier to truth-dominant news is whether a majority of market

This assumes an equitable distribution of purchasing power among market participants, so the only barrier to truth-dominant news is whether a majority of market participants demand it. Unfortunately this is not reality. There are many reasons why statements that are untruthful, or at least tangential to the truth like rage-bait, are paid to be distributed. Sometimes domestic political parties seek to spread misinformation because it will drive their core voters to the polls, or convert on-the-fence voters to their side. Sometimes nation-state actors seek to spread misinformation to cause chaos and disrupt national unity. Maybe an industrial lobby is seeking to obfuscate or misinform about products and their benefits (see the sugar industry's public campaigns for 'low-fat' foods packed with sugar as beneficial to your health). In all three of these examples, the parties supplying the information have vastly more resources to spend on spreading the information than anyone does to combat it, even if it is a net-negative on society, because there is money to be made or power to be had. Business interests can sustain their propaganda as long as they are making money, possibly indefinitely. National political parties can sustain their propaganda as long as there are major interests that benefit from the party's actions, typically also indefinitely. And we all know the kind of resources a nation-state can deploy.