That’s accurate and doesn’t contradict the person you replied to. What they are saying is that SEO was never about fixing a search engine user’s problem; it exists to solve web host’s problem of “we aren’t getting enough ad revenue.”
The same is going to happen with these LLMs once they rely more and more on searching the web: folks are going to find out how to poison the results in a way that pushes users toward their products/services/ads.
SEO should always have been called index poisoning, because that’s exactly what it is.