Does the redesign have any functionality that this addon does not have?
Oh yes definitely! I don’t know what specifically but it improves some aspects of Anki overall, I will leave you with screenshots with and without it.
On top of that, it is also a CSS injector! This is the main reason why I use it personally, I can have custom CSS for (almost?) every part of Anki.
Screenshots without Anki-redesign:
Screenshots with Anki-redesign:
