accessible browsers
You realize that the HTML5 standard introduces a lot of semantic tags specifically designed to aid accessibility tools interpreting web pages?
E. g. <nav> advises screen readers to omit the content of this tag in the initial rendering of the page to offer it later for further navigation etc.
I guess older versions of CSS are creative restriction but HTML5 really only removes old, unnecessary stuff like <blink> <marquee> and introduces more semantic tags like <section> <main> which have no special functionality other than indicate the type of their contents.