Why would it affect ad revenue?

An exploit like this would be abused by somebody who sets up a malicious website to try to take control over somebody's device or otherwise steal secrets from them like keys for cryptocurrencies. These attacks tend to be targeted. Nobody is using an exploit like this to create an ad blocker or even to do ad fraud.

The only risk to revenue here is reputational, and I think that it is likely that the existence of this bug would be less widely known if the bounty program didn't exist and the bug was sold on the black market.