They’re taking information from the page they served you and runs the code they wrote to read the page they served you to ensure what they served you is actually what you’re seeing
You’re accessing the site, you’re continuing to use the site, you are implicitly agreeing to allow the code they run to modify the page you’re on
I fail to see how it specifically being used to check that ads are displaying is any different from code running normally in your browser to change the page without refreshing the page entirely
More importantly and actually on subject: how is this immoral? What moral code are they breaking here? You can argue legal semantics, but legality is not morality. You made a moral argument. How is this immoral?
Google is tracking you on every website that has a “share to Google” icon.
Which means Google has your entire browser history, even if you use Firefox.
If it was just on their own websites, nobody would be complaining.
