They have a choice between either putting that content on their own platforms or watching visitors trickle to competing platforms where they can get that content.

Much as newspapers have a choice between printing news about such actions or watching people buy competing newspapers that have it in there. They print it while putting their own spin on the events.

Really the only difference between the two is that the editor of the newspaper is a human hand while the editor of the internet plaforms is the algorithm. They have degraded their control by handing things over to automation. The algorithm will never be a spindoctor, even with ai.