The problem is not ads, per se. The problem is (a) tracking and (b) ad-based business models who have misaligned incentives between users and advertisers.
If you tell me that Google/Firefox share their revenue with users and their ads don't collect personal data, I'll be rushing back to it.
There are some people however who do see the benefit of trading (directly or indirectly) their attention for services and products. These people should be able to do it without having to give away their privacy as well.
The thing is: we have two different business models. On both of them, ads are a reality. But one of them they are (1) opt-in, (2) private and (3) still give the user the power to "vote with their wallet", even if there is no money directly involved. The other is what we have: Surveillance Capitalism, big players exploiting user data and a total misalignment between producers and consumers. To me it seems pretty obvious which one is better and which one I'd support.
If you tell me that Google/Firefox share their revenue with users and their ads don't collect personal data, I'll be rushing back to it.