For Google, the answer is pretty clear: the advertisers decide what content is acceptable or not acceptable. It is pretty clear (like the parent indicated) that

For Google, the answer is pretty clear: the advertisers decide what content is acceptable or not acceptable. It is pretty clear (like the parent indicated) that the pressure to demonetize is coming from the advertisers. And it's not really "fake news" that I've heard the most about, it's content that is deemed objectionable to their image. Not many companies are going to accept appearing next to terrorist recruiting videos, or racist material, or videos that appeared to be child predatory (all headline-grabbing incidents of late). Large companies also tend to shy away from "controversial" / "radical" politics as well, so there's no question that some of those are going to be targeted. This is the consequence of the nature of the beast: a broadcast platform that lives off of advertisements. You can't force Google to not do what their advertisers want. I see no reason at this time why those with advertiser-unfriendly viewpoints can set up alternative platforms, that do not necessarily need to cater to big-corporate advertisers. At this point (at least in the United States), you don't have the situation in some nations where there is just one viewpoint (the state media) and alternative opinions are silenced not by demonitization, but by police/army force.