You as a young person before, you your mind is already mature to get curious of that, hehe. It was like you are business minded mate. While me as a kid, I only enjoy the advertisements done by big brands. So they hold so many value on my current age.
Anyways, when the brand is already huge, things would have been easier for them to promote and pay the right people to dominate the market evenly. It may be true that the science behind is for the people to not forget them but on my case, I still recognized and would buy products that doesn't have an active advertisement anymore. Though again, it may be due to nostalgia but their quality is also that good.
Sometimes it is not just about how much a brand advertises, but the kind of impression they leave for us to see when they were growing up. True that big brands have an advantage because they already have the money, name and customer base to keep themselves relevant but at the end advertising may bring people to a product, while quality is what keeps them and make them come back later.