I.e., people buy stuff they wouldn't buy if they got honest information.
It works against the main argument in favor of the free market: not the best product wins, but the one with the biggest advertising budget.
Ads just try to drive up sales. This is something we don't need given current energy/climate issues.
There are better ways of bringing supply and demand together. Several decades ago we had yellow pages, and they worked fine. I'm sure in the internet age we can come up with an even better system that doesn't involve user tracking and/or distracting ads.