Immersive reader is a Microsoft Azure Cognitive Services tool to help a user's ability to understand content on a page.
The tabindex attribute has the power to really ruin the logical tab order of any web page when used incorrectly.
Unless a heading structure has been coded correctly a page hierarchy can become unclear to non-sighted users.
ALT attributes are a way to describe descriptive images and a way to make a screen reader ignore decorative images.
Grouping related controls together can help a user understand relationships more clearly between components.