In my opinion, you have it backwards. It's not about what anyone can do with/about the platform. The center of the issue is that facebook/google et al are selling convenience to the public who assumes the platforms are to some extent trustable.

I think you might be reading too much into what I've said. When I talk about individual action, I'm talking about that in all realms: on the site, in person with other people, in their communities, what projects they work on, how they choose to engage in politics: How they can actually make the change they want to see. And that includes taking a stance on how to engage with Facebook et al. IMO the solution to "the public who assumes the platforms are to some extent trustable" has to center around peer-to-peer education of self-responsibility, critical thinking, and choice.