Why might news media outlets engage in propaganda, sophistic objectivity, or sociocentrism?

There are various reasons why news media outlets might engage in propaganda. One of the most common roots of biased media is state sponsorship. Examples of these include China's Xinhua News Agency and Iran's Islamic Republic News Agency. Since these media entities are owned and controlled by the state, they will have an inherent bias in favor of the state, even becoming apologists for the state. In a nation where democracy is strong and healthy, a news agency owned by the state is considered a conflict of interest.
However, non-state-owned news media agencies are also prone to bias. This is because private media conglomerates such as Fox News, CNN, and MSNBC are owned by individuals who might have certain ideologies or political biases. Likewise, they are funded by corporations via commercials and other advertising revenues. The corporations funding the news organizations could have biases towards an ideology themselves.
In some cases, biases and myopic perspectives are part of the news outlet's brand. For instance, news outlets such as Fox News are blatantly right-leaning, besides shows like The Fox Report with Shepard Smith, while MSNBC is considered left-wing. In these cases, the news outlet tends to focus more on increasing viewership and entertaining the viewers rather than adhering to objective, textbook journalism.