Re: $22bn @Mint Sauce
You miss read the text you quoted:
nearly $22bn (£15bn) in advertising revenue was lost last year
Whilst I suspect the $22bn figure comes from the application of the Monte Carlo method, where the individuals sampled simply raised a wet finger and plucked a figure out of the air, the failure to serve an ad will result in no payment to either the website 'hosting' the ad or to the advertising agency, regardless of whether someone actually clicks on the ad or not.
Hence it is perfectly correct to say that the Ad industry is missing or losing revenue (as are websites that depend upon garnering large revenues from the ad's they host). However, for businesses paying for an advertising campaign the economics are probably quite different, given they are wanting to generate real business transactions and not just clicks...