[ohgodplsno]

People with reading disabilities, vision issues, etc are rarely the ones being heavily represented in parliaments. Accessibility is truly a case of things being earned through spilled blood, and while there's probably much fewer people dying because they can't read the text on your website, it's a natural extension of the physical world. While the laws do not say that it should be up to the browser, it becomes natural that this moves to the lowest common denominator. Should it not be part of browsers, the moment any dominant browser comes in (say, Chrome) and implements it would lead to thousands of websites relying on this behavior from the browser, leading to "Works only on Chrome" situations, and other browsers most likely rushing behind to also support that feature.