One thing you notice running NoScript is how prevalent Google is.
Even if a site doesn’t monetize with Google Ads, there’s a decent chance it’s pulling a script from ajax.googleapis.com, and Google still knows that you visited the site from the Referer of the script download.
And lucky for Google, browser vendors (including Google) even decided that caches shouldn't work cross origin so this request needs to be made for every site even if you already visited another site that used the same resource.
Even if a site doesn’t monetize with Google Ads, there’s a decent chance it’s pulling a script from ajax.googleapis.com, and Google still knows that you visited the site from the Referer of the script download.