You have to include the fact that the very clear objective of advertising is to make you consume more. Thus producing more pollution than if there were no ads.
So, even if advertising was technically neutral (which is clearly not the case), it would still be an ecological cataclysm.
One would even argue that the whole climate emergency is created by our advertise/consume culture.
That, plus the industry exists to support a negative-sum game. Past some degree of market or channel or target saturation, the only thing your ad spend does is cancels out the ad spend of your competitors. That, and it fuels the growth of an industry that's happy to enjoy the infinite money printer.
And the services needed to consume said money printer. GCP wouldn’t exist. To be fair, a lot of it runs on AWS so AWS’ business would take a serious hit as well.
