If you use Chrome, Google can use a network protocol for tracking and ad delivery that can't be seen or blocked by extensions. TL;DR: You really shouldn't use a web browser made by an ad company.

"AdBlock Plus, uBlock Origin, and other extensions cannot block QUIC requests. Recommended best practice is to disable QUIC from the chrome://flags/ URL."

https://blog.brave.com/quic-in-the-wild-for-google-ad-advantage/