The assembly / bandwidth / cpu / etc argument really shines for limited platforms. E.g. if you're on metered internet, loading ads costs you money. If you're on a small device, playing ads costs you power, meaning you have to find a charger sooner.

Computer ads aren't free for the people subjected to them, since we're the ones that have to do the work of displaying them. Compare that to paper / magazine ads add a few grams of weight and a bit of volume, but rarely in noticeable amounts, and billboard ads that don't cost the recipient any resources by being there (except maybe having to step around them).