Informing the target that a product exists is a small part of advertising. It's important for the small players, but for the big advertising spenders it's much more about communicating values, trustworthiness, emotions. Building a brand image, and maintaining brand awareness
Just the fact that you are running an advertising campaign of a certain size used to be a signal in itself. Same with advertising in or for subcommunities. That signal is heavily dilluted by targeted advertising
Similarly, personalized pricing is removing signal from the price. Sure, price was always a noisy signal, but better a noisy signal than no signal