Targeting is a thing from the last decade, we did fine before and we will do fine after.
Once contextual advertising once again becomes the best option because targeted ads are banned, it will be worth the full price again.
Also, I think it will in fact work better. There's no point showing cosmetics ads on a tech site to a guy like me just because I bought eau de toilette last week. Really no point because I buy one bottle of the same stuff every few years. Any contextual ads that that site would have shown would have more relevance to me. Real world example.