I produce media and I sell it to Google. Google in turn produces an interested audience for that media and sells their views to advertisers in the form of ads served. Advertising agencies in turn produce ads to sell to (for example) GM… GM is the ONLY party with a material interest in the ad actually being viewed by the (potential) consumer, as they’re the only party who can convert my media into a GM vehicle being sold. If anyone in that chain can consider an ad blocker theft, it’s GM… that’d still be wrong, of course, for the same reason ignoring a billboard on the freeway isn’t theft.
When you lay a trap and your prey refuses to be caught they aren’t harming you.