If web sites started serving an HTTP header saying "browsers with ad blockers are not welcome to view this content", I would allow my browser to honor that requ

If web sites started serving an HTTP header saying "browsers with ad blockers are not welcome to view this content", I would allow my browser to honor that request. That's more convenient than solving the AI problem of identifying and filtering out all the garbage content that exists for the sole purpose of drawing eyeballs to ads. Just tell me up front that it's garbage.