I am very skeptical about the implications of this take. You paint this as "big data companies are actively lobbying/threatening politicians to enact legislation helpful for big data using their big data troves." There are politicians who work in good faith and have non-controversial backgrounds who would not be liable to these blackmails and still don't work hard enough to enact legislation to protect citizens. This is not a big data conspiracy as much as lack of political willpower.
If the information is stored on servers in China, then the Chinese government has it as well. Maybe you aren't a Chinese citizen so you don't care, but it's at least worth considering.
The politicians we elect to craft and enact legislation that affects the big data companies are always at risk of being essentially blackmailed by those companies with the incredibly detailed and personal information that those companies have on politicians.