Is targeted advertising even successful?

Our data moves all over the internet so that advertisers can directly advertise to us, but I’d say that 90% of the ads I do see (I try to block as much as I can) are for something I already purchased. I bought an Apple product and now I have seen a few ads for it on YouTube. I got new insurance and then I started seeing insurance commercials.

Is this how it’s supposed to work, because I don’t get it? What’s the point of trying to convince me to buy a product related to one I just purchased. I thought targeted advertising was supposed to predict what we might want to purchase based on past purchases.

What am I missing.