It probably haven't had much practice. It's not like the internet is shock full of texts tagged with the IQ of the author. It is, however, full of SEO texts, Wikipedia articles, and /r/askscience answers.
There are also 1 in 6B people with an IQ of 200 or above, and I imagine they're not prefacing every public forum interaction with: "I have an IQ of 200, here's my take on..."