Earlier quoted context omitted.
I wrote this comment elsewhere below but it still applies The State has always been able to look up phone records, bank records, land records, criminal records, medical records etc etc as in order to pursue justice and prosecute. How is this any different?
Scale. 40, or even 20 years ago, the State might have been able to note a record of phone calls, postal correspondence (look up "postal covers"), some financial purchases, periodicals subscriptions, and with a great deal of effort, some of my travels and movements, mostly limited to specific port entries and exits, and air travel. But unavailable would have been: dictionary queries, encyclopedia queries, books read,…
Anyway to get to your main body I agree and note what makes the scale bad ultimately is abuse potential for it. For a fantastic example being able to look up details of everyone but only 500 years or more ago wouldn't be abusable for instance because everyone is long dead and it wouldn't be viable to try to change ownership based on it because it already diverged for several generations. Even if you could backtrace they couldn't be reconciled very effectively.