From your link > Yes, Facebook uses SSR heavily. However, according to Lee, there are very few areas where they use React to render components on server. This

From your link > Yes, Facebook uses SSR heavily. However, according to Lee, there are very few areas where they use React to render components on server. This was primarily a decision based on their server environment which is Hack. Yeah this is my whole point. That person was attempting to school devs at Facebook on the benefits of server side rendering in PHP. And whatever you said was quite niche.