If you don't think sites have a fundamental right to push ads to sustain themselves (as I don't), then blocking the request is the best place to do it for performance reasons.
But even if you do believe in that right - the site and advertiser care about a single thing: a human being seeing the ad. Serving the Ad request is not just useless for their purpose, it is actively costing them money, and potentially muddling their data.
I disagree. The site just wants the advertiser's money. The advertiser wants the human to see an ad.
Why not have the browser /dev/null them, and click a few for the heck of it? It would be in the user's interest.
Most people sometimes leave the room while ads play on TV. The advertisers know that and work the percentage of pepole that do that into their pricing, etc.
Also, non-organic click fraud is rampant already (and maybe even the majority of clicks). /dev/null + click would at least route ad income to reputable sites that at least have some human readers to view future ad impressions.
This is of course ripe for abuse, but that's just synonymous for digital advertising in general. I don't consider it any different than me hitting mute on the TV during ad breaks or getting up and going to another room during that break.