There is a long list of people, companies, and governments that have access to your information and the things that you do online at any given time.
Your phone is not private.
This chart shows how many third-party websites were connected to my browser when I pulled up Dictionary.com. Some of these things are resources and external tools, but the majority of it is tracking. There are hundreds of companies that exist to track you, and to sell your information - everything from what sites you visit to how long it takes you to read a paragraph or how much of a video you watched - to each other, and advertisers, and whoever else.