The user being in control of access to his/her own data is not a concept that should frighten any legitimate business people. But businesses being in charge of access to a user's data is absolutely a concept that should frighten users. The power of determining access has to be shifted back to the user where it belongs. If some businesses that specialize in "data brokering" are harmed because users are suddenly able to choose to disallow them access, so be it.
Again, allowing businesses to influence and determine who gets to access a user's data is literally the reason we're in this predicament in the first place. Solve that stuff separately if you want, but under no circumstances can end runs around the user's ownership of their data be allowed.
It seems to me like there are two important issues currently. There's access to data, but there's also how influence works and who controls that. Right now, social media companies decide what rises to the top of your feed.
The current situation is that if you want to be part of the Facebook community (for lack of a better word), you need to let Facebook decide how you see that data. I could see an argument that some kind of federated system might allow different lenses where you could still communicate in a social media way but different things could rise to the top.
Anyway, the point is these two concerns seem to be at odds with each other. If you don't want one party to have the power they get from being the only party in charge of processing the data, then you need multiple parties to have access to the data.