The social aspect of Reddit is a massive enhancement of this. It's one thing to see a headline on WaPo or NYT. It's another to see that on Reddit, with dozens of commenters all posting takes that advance the same frame or line of reasoning, upvoting each other, congratulating each other on how smart they are, etc. What you don't see are the interlocking moderators on all the top subs or the fact that people are frequently banned from completely unrelated subs for political reasons based on their posting history. The result is an echo-chamber that is a 90% match for the editorial stance of WaPo or NYT at all times, except it looks social and organic, and therefore extremely convincing to onlookers.
It's an interesting study in human self-organizing behavior. We like to see our opinions confirmed, so we like sites like reddit, which breeds this exact behavior. This leads to the groupthink or hivemind as reddit users call it.
There are so many sleights of hand type maneuvers you can pull to moderate sitewide. Tiktok, for example, bans LBTQ content not outright but just sets some flag in their database that ascertains the posts never go viral.