Creating a website that’s “accessible” means that people with disabilities can perceive, navigate, and contribute to the web. Conversations on web accessibility are usually associated with the aging population; senior citizens are more engaged than ever, making up 24% of online users in North America - with 40% of those shopping online.
There are many guidelines available for optimizing accessibility, from government and educational websites to dedicated communities, such as W3C. Do you ever go on a .GOV website and see big fonts, a simple layout, and basic colours? This is the result of accessibility in the works.
The Hubnest Team in New York used FACIL'iti as a reference in their work towards a more accessible web - an article called "Rethinking web accessibility and why it matters".