The article makes a good point, but I don't think I'd call it the death of authenticity. A deceptive banner ad is just the new version of a fast-talking door-to-door salesman. It's the method of reaching consumers with the lowest barrier to entry, and that's why it is so popular with the inauthentic.

In the days of expensive print advertising, the investment required to take out an ad was often enough of a barrier to legitimize a business to consumers. The model has changed, but I believe consumers are still looking for companies that make some kind of investment to prove their authenticity. The new version of the expensive print ad is the investment in time and effort required to gain the trust of industry experts and influencers.