Yeah, that one confused me too. There’s a checkbox when you setup wordpress the first time that says something about search engines, maybe that’s what he’s referring to? Could be a number of plugins that help with some aspects of SEO that google will soon penalize for.

My experience with high traffic sites is that most of the things that helped our SEO were things I’d consider basic hygiene along with generally better than average content. There’s not much wordpress can do for that, in fact it will actively hurt you with it’s slow page generation if you don’t have a good caching layer.

WordPress won't remove the need to write high quality content, but the markup is very easy for Google to parse and with the Yoast plugin all of the structured data is automatically handled. WP also automatically adds alt tags to images and all the other bits of metadata Google likes.

Yoast has an incredibly feature-rich free version and is very easy to use for content creators. Focus-keywords, schema markup, meta title and description lengths and so much more. They've also recently extended the plugin so you can access a post's metadata really easy when querying the WP REST API (or GraphQL API), this comes in handy when using WP as a headless CMS. I don't know of a comparable solution for React or Vue but I would be glad to hear about it.