Sounds like there is no connection MS Word and SEO (Search Engine Optimization). But there is. One of the parameters which is important while performing SEO is the ease of reading of the web content. Easier the better.
But how do you know if your text is easier to read or not? That is a feature MS Word has been providing for over 2 decades. And mind you, if you want your web pages to be more readable, why not treat our documents the same way? Think about it.
Many SEO tools have a built-in method for checking the ease of reading. I use the Yoast SEO tool. It uses the Flesch Reading Ease score. If the score is above 65, your content is easy to read. Max score is 100.