I didn’t understand the point of one politician not being able to see what the other person finds on Google. … Google does not “create” articles or news, it just finds them for us.

And answer of your search query isn’t often as simple and objective as finding the answer to 2 + 2. More often Google decides what is the right answer, rather finding the right answer. Say when you search for “Free Basics controversy”, which is a more likely query than “Why Free Basics is bad?” especially if you are aware of various aspects of the issue. Here you are asking Google to decide on your behalf what is the best resource on the web that summarizes the controversial. If you all you get is articles from Zucerberg and co then you may never get to know and understand the arguments from the other side. Here you are letting Google decide, on your behalf, that the other side is not worth listening to. A person who has a fuller understanding of the issue will say that Google is clearly being biased but that person will have no way to prove if it is just you or everybody. Personalized search gives Google more leeway to manipulate you without you getting to know that they do.

Another point to note is that just because something is decided by an algorithm doesn’t mean that it is unbiased, and they can be biased in certain directions without you or Google intentionally doing something malicious. For example, a recently paper showed that the image search exaggerate the existing occupational gender bias. Personalized search make it harder for us to uncover these biases and ultimately fix them.