I agree with your sentiment. But where I struggle is: to what degree do each of those ads “represent one less person who would have been paid” versus those that represent one additional person who would not be able to afford to advertise in that medium.
Of course that line of reasoning reduces similar to other automation / minimum wage / etc discussions
It reminds me of the piracy lawsuits that claimed damages as if every download would have been a sale
The extreme opposite idea that no unlicensed use of software is a lost sale is likewise a fantasy.
Obviously there's some mix of the two, but given then I've seen AI used (poorly) for both TV commercials (in expensive time slots) and billboards (I think expensive as well, but I don't really know) where you know they can afford to pay "real people" to do it, there's definitely a noticeable amount of real replacement.