We’ll do our best not to show you ads about the topics you limit. In some cases, you might still see an ad containing images related to the topic you’ve limited. For example, you might see an airline ad featuring someone holding a glass of champagne. This isn’t an alcohol ad, even though the ad shows alcohol.
In other cases, you might still see an ad about a topic you’ve limited if you search for info about one of those topics or you watch a video related to those topics.
So I can make suggestions to Google for ads but not truly disable topics.
I mean, the point is about profiling you for ads. If you search "buy a car" and get car ads that isn't really about the personal profile Google built up about you over time.
FWIW most ad networks already let you do this. Here's google's https://myadcenter.google.com/home