About how Pixel is more private.. Pixel 'only' has Google's tracking; other manufacturers have their own tracking, *on top/in addition* to Google's tracking.
Installed GrapheneOS and adjusted my google settings to track everything they can, then I checked to see how much data that got collected, it is almost nothing.
Under GDPR you have the right to download the data they have about you, so google has a page where you can do that. That being said I doubt that is everything they track, I'm probably still getting fingerprinted and tracked by ip, but still thats a lot less info collected on me and most importantly that data is less valuable to sell.