A lot of what is labeled and sold as "SEO" might as well be diet fraud. Plagiarism, false advertising, astroturfing, etc. It certainly isn't just letting the Google bot know what your website is about.
Say somewhere in the bowels of their ML pipelines, features that get scored include things like "has a favicon.ico and it's unique and not seen elsewhere". Well, then doing that isn't really fraud to me. It's just adding "proxies for quality" so you aren't dinged for not having them.