Not exactly accessibility features, but a more general usability, even for people without disabilities. I personally noticed the lack of a scrollbar when I wanted to check how far through the article I am, but another common use case for those is to actually scroll through the document (particularly for skimming of larger documents, for which mouse wheel, space bar, or Page Down key are too slow, or in more rare situations when they are not easily available).

Unfortunately tinkering with visual presentation tends to conflict with the principle of least surprise, user settings, or even basic functionality.