Here’s how I know.
I’ve been blogging for 10 years. I’m no Ernest Hemingway but I’m reasonably articulate and have several hundred thousand social media followers.
When I started seeing poor readability scores I began to test. I posted one Nobel prize winner’s article – an article written by three veteran reporters in the Washington Post and one article from a well-respected reporter with the Huffington Post.
All three articles got a “poor readability”. Now here’s the rub. – Just for shi#ts I put in a table with six cells each cell containing six Alpha characters – six a’s six b’s and so forth. That post scored a Yoast “readability ok”
I brought this to the attention of Yoast support. The response was “we’ll get back to you”.
The Yoast readability score is not trust worthy much like their new internal linking count. IMHO