I expected years ago that the government, at some point, would realize if they are interested in the data that they could purchase, other nation states would be as well and could use it against us. Therefore the logical conclusion would be to declare collection and sale of such data to be a matter of national security and strongly restrict it as such.

The detail I failed to understand at the time was just how much money there is in data collection and brokerage.

The other detail you missed was, that this world is mostly not run by sane governments that do the rational thing you would expect from them.