Relatively speaking. These patterns were extremely unlikely to be uncovered (unless, again, you were a worthy enough target to allocate resources to); and therefore such information might as well be considered "effectively" private.
What you’re upset about it how much more easily people can connect those pieces of information and access them.
Yes. The pieces were either not available, or would be way too resource-intensive to piece together: simply to generate the type of insights outlined in your scenario.
The cat can’t be put back in the bag, what you gotta do is be one of those psychopaths who use tag obfuscation and wear face masks around.
A defeatist mindset can only result in defeat, while we're still amidst the rollout. I'm not quite sure what you mean with "tag obfuscation", but there's nothing "psychopathic" about wearing masks, solely in an effort of protecting one's personal information, from potentially being used in a malicious manner. What is psychopathic however, is subjecting innocent persons to that sort of tyranny, and victim-blaming them whenever they resist.