Tracking usually happens across websites, meaning the information is shared with third parties outside the people running the website where you accepted the cookies. Knowing your interests, behavior and preferences makes you prone to manipulation. The selection of information shown to you will be crafted such as it maximizes engagement. For example, showing you information that upsets you, in order to get you to react. Or just information with a slant or spin to influence your opinion. Nobody is immune to being affected by the distribution of what they are being shown.