I have many problems with a post like this.
As far as I remember there has never been such thing as an "unstoppable monopoly", why would anybody assume Google is going to be one?
Google has no "monopoly". They are chosen by the majority of people for their quality services. The day, Bing is better than Googlesearch, I call it a day for Googlesearch. The marketpower of Google is only lent.
"If Facebook has this much data on us and has shadow profiles of people who don't even use the platform, then we should be very worried about the amount of data Google has on us."
Why? I see no reason to worry.
From my perspective the cambridge analytica is totally overrated.
To make things clear: I find it problematic, that they had access to data, which they shouldn't have had. But there is a discrepancy between the effect they said they had on votes and the real effect. Yes, there is an effect - but much smaller than we believe.
There I would like to disagree partially.
Yes Google has tons of (meta-) data about many people.
But I do not believe, Google having any power over people because of that fact.
I find it more dangerous when my local government had full access to this data silo.
To your question »Or should we leave things the way they are?«
We as - currently nationally separated - societies should reflect upon that topic. At the moment I am undecided which way to go.
We're a place where coders share, stay up-to-date and grow their careers.
We strive for transparency and don't collect excess data.