Frankly, I'm surprised it took them so long to say this publicly. For over a year, Mozilla has had a de facto conflict of interest when it came to their stance on advertisements, so take anything they say about their necessity with a huge grain of salt...
May 2023: Mozilla purchases FakeSpot, a company that sells private data to advertisers. Mozilla keeps selling private data to advertisers to this day.
June 2024: Mozilla purchases Anonym, an AdTech company.