I think the problem is basically the first step that you propose:
>>Nah, that's not how it's done. In 2020, when the most relevant media outlets and tech companies are controlled by a small oligarchy, the way to create change is from the top down; get the establishment on board, and have them create a narrative favorable to your side, and silence (and if necessary, crush) anyone who gets in your way.
How exactly would you get them to do that? Especially with regard to the media. To me, this plan ends before it begins. And I don't see how things are meaningfully different in 2020 than in the 1970s.
If nothing else, the social movements literature shows how powerful a small group of people can be.
Any plausibility here is kind of fully killed off at the end when you state civilization is "destined for collapse."