You are assuming that search ranking is determined solely by an intelligent AI. This is not how search engines work. Search ranking is determined by people that

You are assuming that search ranking is determined solely by an intelligent AI. This is not how search engines work. Search ranking is determined by people that decide that sites like A must be ranked higher than sites like B, update the rules and then maybe AI is somehow used to apply those rules made by humans. So it shouldn't be difficult to explain why the site is ranked higher. But I don't think Google will ever disclose that secrets.