Advertising-funded media is inherently plutocratic, in which those with the most money influence direction. Sometimes more overtly than others.

There've been many treatments of this: Jerry Mander's Four Arguments for the Elimination of Television (1978), Edward S. Herman & Noam Chomsky's Manufacturing Consent (1988), Neil Postman's Amusing OUrselves to Death (1985), Hamilton Holt's Commercialism and Journalism (1909) <https://archive.org/details/commercialismjou00holtuoft/page/...>.

That last is particularly good for a number of reasons, including that it's short and information dense, and lays out the clear conflicts inherent to advertising-driven media just at the time it was first gaining influence, and at a fraction of its present size and influence.

If you prefer video, media critic Isadore F. "I.F." Stone gave an excellent 1973 interview on the PBS series Day at Night on the state of newspaper journalism in the United States, contrasting the relative independence of big-city dailies vs. rural papers. The former were large enough that no single advertiser could threaten editorial independence.

Link will offer a choice of instances to redirect to: <https://redirect.invidious.io/watch?v=qV3gO3zxQ1g> (video).