The tips included in the article are indeed useful and will contribute to the improved readability of your website. In this article, I’d like to extend the list with a 4th tip.
The article mentions that we should consider our font family and size.
An additional point to this would be the space between the lines or line-height. If the text is too dense, it will negatively influence readability.
Take a look at the below two screenshots, the difference speak for itself.
A2Hosting’s article quotes the Flesch reading test, however that test doesn’t evaluate line-height. Despite this, it’s clear that for the human eye it is a major factor when it comes to readability.
Especially if the font family and size are not fully optimized, line height is important.
So next time when you are writing content, make sure that that the line-height is on point.