I never bought an advertised product in my life. If any of the brands I buy starts advertising Im going to look for something else. I look for things, it’s not the other way around.
I suppose they're being a little hyperbolic but honestly plenty of folks just buy off brand generic products at ALDI. Pretty easy to avoid advertised stuff if you just shop at discounters. Popular here in Germany even among people who are well off.
Cudos for you. I try something similar, I do not buy a product if I believe I saw its ads. It is a light version of your strategy (I'm not going to watch ads to know what is advertised and what isn't), but even it doesn't work in all cases. For example, my cat eats advertized food now. Not all of it though, but dry food is advertized.
Some of the most life-changing products I own were shown to me in an ad. Might not have bought that exact item, but the knowledge of that type of product even existing?!