Some advertisements are malicious attacks on your attention to build brand recognition and entice you to buy things you don't need.

However, I think advertising in itself isn't inherently evil. If a chess website served non-tracking, static (no-JS) banner ads about relevant products (maybe, specifically, chess products?) to offset costs, I don't see anything wrong with it. Of course the question is: "what is a relevant product to advertise next to chess?" Would... other board game advertisements be acceptable?