[knowledge-clay]

> This will not bother most people. Most people are willing to use GMail, even though it snoops on their private emails and uses that info for advertising purposes.

While I agree with your larger point and am no fan of Google's privacy practices, they stopped this specific behavior in 2017

https://www.npr.org/sections/thetwo-way/2017/06/26/534451513...

[Animats]

No, at that time Google issued an announcement that at some future time they would stop doing that. However, Google did not modify their terms of service [1] to prohibit them from doing that.

    "The activity information that we collect may include:

    Terms that you search for
    Videos that you watch
    Views and interactions with content and ads
    Voice and audio information
    Purchase activity
    People with whom you communicate or share content"

Google does write "We don’t show you personalised ads based on your content from Drive, Gmail or Photos." That's a narrow exclusion. That info could still affect your YouTube selections or search results.

[1] https://policies.google.com/privacy?hl=en-GB#infocollect