Most people do not know about, much less use ad blockers. An old colleague of mine started a local pizza restaurant. The first week after she set up Facebook and Google ads her average daily customers jumped 40%. After dialing it in and perfecting the ad campaign it's up to 90%.
Targeted ads work. If I search Google for a pizza joint near me, a pizza ad is indistinguishable from the correct functioning of the search (except that it put itself at the top of the list).
Non-targeted ads? Most people have mental filters that weed them out. They're just background noise now. (But oh, the bliss when the noise stops...)
Ads unfortunately do work.