I can echo that, which is why I doubt that neither advertising nor design can become fully automated by AI
I could see 2 things happening in this space:
1) AI may make ordinary advertising more accessible for smaller budgets
It'd be similar to bootstrap or material design, in that they help non-design-driven products with not looking obviously cheap. But after adoption of said frameworks, products will look more alike. Hence the need for differentiation to gain more attention.
2) Given the said need for differentiation most revenue lies in the combination of inputs by humans and AI.
For example when given the fundamental parameters that define a brand's design language, an AI could iterate on that to churn out new designs that continue this language with the human fine tuning the direction.
An AI then could also deliver options of where to steer the design language in general, e.g. for car-designs:
a) add an aston-martin-like front grill (go with the general trend)
b) do the exact opposite of a)
c) allow just small changes to current design language and never mind the competitors
etc.