I am completely confounded that I have not heard of any real legislative proposals to establish a clear separation of duties in regards storing data and selling it.
There is an obvious conflict of interest if you both have my data and are granted free reign to do what you want with it (via click through agreements that modern society is now dependent upon) you have unfair leverage over me.
If you are able to do this en mass without much competition... I'm thankful things haven't gotten worse than they are.
Something similar to Glass-Steagall is desperately needed in the digital era. Hopefully somebody is working on it...
Strict enforcement policy on cold storage data warehouses. And sensible policy for the app providers, like not caching PII.
Implement and enforce at the fed level using this division in a manner that is something akin to Glass-Steagall.
Owning data should not be something providers can ever exploit.
[edit]: I also think this could be used as a means to break apart Big Tech