Err, this payment doesn’t block ads. It only switches off personalised ads. So, the user is still seeing ads, just not targeted ones. So the site is getting both user’s money plus ad money. And technically, I am not sure how privacy preserving this is because you will still need to create an account which technically leaves you vulnerable to tracking.
I got a similar phishing mail as well though not for my primary email account. Most of them just redirect to a similar looking login UI and ask the user to enter password.