> That is why we have them
evolutionary objectives are not rational. Nor are they particularly up-to-date, especially sugar cravings. Addictions, vices and impulses of many kinds are not at all rational, and it is a virtue to have the willpower to resist them.
> (1) what people didn't yet know existed
This is far from the only objective, and the substance of many ads demonstrates this: why do brands like coca-cola pay top-dollar for superbowl ad time? You would think they are well known enough..
> (2) what everyone else knows
Ads are not knowledge, it is common cultural reference for the purpose of advertisement. I don't see the value in this if you are not an advertiser.
> Ads work by and large because people want the products that the ads are selling
If we follow the same logic, no one would object to ad blockers, b/c the people who want to see ads wouldn't use them.