I argue that ads are stealing resources from me not only on my Mac but cognitively. They are intrusive and cause interruptions which takes time to recover from. I used a paper from Datamation (I think) that worked out the mental cost of various types of interruptions. The worst being off-project interrptions which were estimated as needing 20 minutes recovery time to get back to the point one was at before hand; all ads are in my grumpy opinion off project. Esterling was the author of the paper I seem to recall. (Can’t for the moment find my old spreadsheet that included these costs and applied them to software development man-hour estimates.)