i had to create a ticket in a repo explaining why blocking a whole domain instead of a single subdomain was actually pretty bad. they approved it and reverted the change.
finding where exactly i had to open the ticket and what to write was a “down the rabbit hole” experience.
Sounds like perhaps your task was to ensure a company's ads got through an adblocker?
The default lists used by uBlock for example include things like error tracking telemetry, Sentry for example.
I can see why people want to block that stuff (privacy) but it’s not exactly an “ad”
they were blocking a whole domain instead of blocking the ad-serving subdomain.
the issue was rectified, the main domain was replaced by the ad-serving subdomain.