Look I'm not saying you can't live a low ad lifestyle. I don't have cable or network TV and run ad-blockers on every device I own. And yet I can look around my home and see numerous products purchased at least in part due to an ad. The Retroid Pocket sitting on my table, the M series laptop sitting in front of me. The Sony TV across the room, the game consoles under it. Heck the dog at my feet was the one I adopted because I went to an adoption event being sponsored at a local business. Even when I'm seeking a specific product out and then seeking out information, I'm looking for reviews and a lot of those reviews are given sample/free product for the purposes of making their review. That's an ad. I might be able to place more trust in that review if the reviewer doesn't give the product manufacturer editorial control they way they'd have in a sponsorship, but you can be damn sure if sending free product to independent reviewers wasn't paying off in terms of higher sales, the manufacturer wouldn't be doing it.
I've definitely investigated and eventually purchased things I first learned about through an advertisement.
Mind, usually that was from print ads in things like magazines/newspapers, the occasional direct mail ad like the old Fry's electronics mailer or movie trailers. Online ads are overwhelmingly ugly attention grabbers for things I have zero interest in or no time for when displayed.
I myself usually choose to watch trailers for movies, look at job ads and housing ads when I actually want to watch a movie, change job or move house. What pisses me off is the 99% of ads in my life that are just blasted in front of me online and in public.
It's probably silly and the answer is just that they are, but they at least meet two different types of advert to me, personally.
I would partially agree with OP in that I can't believe any adverts I've ever seen have influence a purchase from me. I actually quite often blacklist brands and products for aggressively marketing to me.