Then you serve the ads on the same set of elements that also contain critical content to the user. You can't block ads from Twitch / YouTube with a rule if the ads are baked into the stream itself. Same goes for any other kind of "element" that doesn't explicitly set itself apart from the actual content.

The ads have long ago started evolving away from a simple "here's an ad neatly placed into its own semantic container so that blockers can target it".