Google owns youtube. Just about every website in the world has google code plug into it.
Google offers a free service to companies that allows companies to track how there web site preforms called Google Analytics.
Every site I develop has analytics plug into it. I have attempted to get the company I work for not to use Google Analytics, they insist because it is free.
Google also host CDN servers, that have JQuery files for website to link to also. If you block Google Analytics they still get you if the website is link to the CDN server for JQuery.
Even if you do not go to the Google search engine they still know what websites you visit via the CDN. Facebook is also tracking on multiply sites.
Very hard to go dark, but there are ways to do it... Example: Buy a laptop with cash 300 miles from home, install a secure Linux operating system, run VPN etc, and only connect from free wifi spots from a parking lot with no cameras. Never use the laptop for home entertainment, use for business only...
Yes. I understand. This is why I expect google to eventually become highly regulated by the government, just like power companies.