Discussion of the free-press in america or elsewhere invariably suffers from lack of historical perspective. Without oversimplifying, the press has always been biased and ideologically motivated to a degree that few appreciate. Because of "all the president's men" and other films lionizing the press' infallible, dogged, ruthless dedication to the truth, people suddenly believe that every journalist is "supposed to be" a paragon of truth-seeking objectivity, dogmatically devoted to the dissemination of "truth to power", but historically and today and even during watergate, the press was a gang of jackals doing yellow muckraking. This has its purpose and we shouldn't hate journalists for doing their job, but it's a complete category error to assume that the press is there to report honestly and objectively.

Why? It’s not clear to me that the motives of a small group of people paying to control the news that I see are better than the motives of a variety of companies trying to get me to buy razor blades and Jeeps. At least in the latter case I know that “big razor” cares about selling razor blades. Who knows what big donors are trying to get me to think.

Why is being beholden to advertisers who just want to make a buck better than donors with specific political goals to change and shape society how they want it to look. (Eg anti-abortion movements.)

...is there a difference? The donors tend to have just as much of an agenda to push

"beholden to donors" is a nonsensical phrase, unless "donors" is defined with a wink, a nod, and air-quotes.