You’re saying that doing this would drastically decrease ad revenue. Which is what I’m saying too: it’s about money, not necessity.

Would a site like SO be unable to survive without ads that run arbitrary JS? I don’t know. Even if the answer is that they must do this to survive, it’s still insane that content companies let randos inject arbitrary code into their pages. If this is so entrenched in the industry that there’s no way around it, that just means the industry is insane.