Discretionary income is measured in dollars/time, cars are valued in dollars. That’s relevant because cars are affordable to middle class Americans because of _financing_ (also because of mass production). Your car payment deducts from your discretionary spending while web advertising does not—without web advertising you would need to subscribe to the websites and services you consume and that would come from your discretionary dollars. Whatever your views on the matter, getting rid of advertising isn’t going to come for free.