Google making ad auctions more efficient and "state surveillance" aren't the same thing. Did you legitimately not know this or are you being intellectually dishonest in your argumentation?
Google making ad auctions more efficient becomes state surveillance the instant a subpoena arrives at their door. You might believe you are safe from a subpoena because you haven't done anything wrong, but you would be wrong about that:
* Things like geofence warrants are used to surveil people who are merely within a given radius of a crime.
* Subpoenas don't have to be for criminal cases, they can also be civil or investigatory (eg congressional subpoenas).
* Things you don't think are wrong are often crimes. Abortion clinic visits in Texas are the most obvious example. Other examples are things like using someone else's WiFi without permission, using a fake name online, or carrying around things like screwdrivers (which are a burglary tool) or permanent markers (which are used for vandalism). Estimates suggest that the average American breaks 3-5 federal laws per day.
Copy and paste from elsewhere because it's the same talking point over and over: big tech is not the government, and your complaint is with the government. The FBI could just as easily setup a StingRay network [1] and capture all cell information. The only protection against that is robust digital civil rights legislation protecting Americans from governmental over reach, not lampooning big tech companies for having data. It's not like Google is willing to just shovel data at anyone who asks nicely, they will actively fight the government on nominally lawful requests it thinks are unreasonable/won't hold up to further legal scrutiny [2].
If you're going to go after someone, at least go after the right people.
Stingrays and other technical things that people could do are a lot more expensive than just asking Google or Verizon for their records. Also, that kind of indiscriminate tracking is a fourth amendment violation, so the government actually can't do it legally (and the evidence gathered by such a technique can get thrown out in court). Both of those things make a big difference.
The right people to go after are the ones who are not bound by the fourth amendment and who are creating a huge pool of data that is available for the government to grab. Technical solutions that collate data have been very useful tools for government overreach over the last century. IBM's census tracking system in the 1930's is a very well-known example of this sort of technology: a well-meaning innovation that efficiently organized Germany's demographic data and made it accessible... to the Nazis who wanted to find Jews.
If you were able to fight a subpoena for your own records (for example, because you owned the data instead of Google), I promise you that percentage would be a lot lower, solely because the incentives are different. Google doesn't particularly care about protecting you. Google cares a lot more than that about protecting its status with politicians. What this means is that they will do the minimum possible review on a subpoena for data on your account to not get sued by you.