You’re putting too much faith in the talent and insight of marketing executives. Large companies throw tens of millions of dollars at their marketing department. They’ll spend the money on a diverse ad campaign that ticks boxes, not one that is actually effective. People don’t buy based on the commercial they saw last. People buy what’s shoved in their faces.

The most effective ads I’ve seen in my lifetime have been podcast ads. I don’t remember shit I see in mobile apps or on most corners of the internet. I could personally sell Blue Apron or Harry’s Razors for all I’ve heard about them on podcasts though. The smartest companies allow the podcasters to joke around in their ads too. My Brother, My Brother, and Me will say some borderline offensive but hilarious stuff in their ads and I’ll be damned if it doesn’t keep me listening to their ads and hearing about the products being advertised.

They wouldn’t do it if they didn’t think it was effective.

You’ve forgotten the second layer of advertising, convincing companies they need to buy ads

With very, very few exceptions, any time I see an ad I make a mental note to never buy that product. As such, most products I am familiar with(presumably because I saw an ad) I will not buy. The exception is pretty much just Hershey’s chocolate bars, I can’t live without them.