Can someone point to any situation in the past where the conclusion was "good thing the ads were less targeting to my interests!"
So, even if you think Google will always have your best interests at heart, the governments they work with certainly don't. China could exploit their knowledge to target dissidents. Would Google do that? Perhaps, just censoring internet was anathema to Google in their early days, now Google respects Chinese censorship.
To be honest, I'm not comfortable with my own government knowing what I want to read online or what I say to my friends, let alone authoritarian ones. The future is pretty much already here on that one though as government already does.
You should be thinking more about the future.