I don't see what opening Facebook's API would buy us. You'd get different interpretations of the feed, but you'd still be siloed into whatever feed it was you accessed. Cambridge Analytica used FB's data to manipulate the feed and thus the users, but no feed algorithm is going to prevent that. Just the opposite: people would find it even easier to choose a feed algorithm that siloed them further. You could jump to a different one -- but would you?

I don't think it would return nearly as much power to users as he imagines. FB won't make quite the same mistakes as they have in the past, but an enormous amount of information is still public knowledge -- putting your social life in public is the whole point of a social network. People enjoy putting themselves out there and voluntarily, voraciously consume what others put there too. No tech tweak is going to change that, or limit the consequences.