Also, accessibility numbers are almost always measured very low because people who need those affordances aren't even attempting to use it, since so much software ignores it. Years ago when browsers let you lock font sizes, I heard many times from both designers and usability "experts" alike, "well, it's not a big deal nobody ever changes the font anyways", not realizing their own self-fulfilling prophecies.

I've always loved that the Kindle, even with such a simple use case as reading a book, supports so many ways to see it and interact with it, so even people without vision or motor problems can use it the way they like best.