Did we really not know that prior to 2016?
Did we really not know prior to Snowden that the NSA, GCHQ and all the others spied on the populace? There's a market difference between knowing in the abstract and understanding it as "this is happening. Right now. Here."
But conversely, it was well that Obama used data analytics to enhance his campaign, using techniques extremely similar to Cambridge Analytica's.
The important difference being users of the Obama for America app opted into sharing their data for political purposes, whereas CA claimed to be a personality quiz to secretly harvest data for political purposes.