I think you are massively underestimating just how much ads pay for, and how much economic activity they drive. If you remove ads, the prices for everything would increase massively (even after accounting for the lack of advertising costs) and even fewer people could afford it.

Sure there are definitely places that have too much, and the overall implementation and UX of ads online is poor, but advertising itself has enabled a lot of people to have access to many things they otherwise would never have.