I've recently switched from Markdown to ASCIIDoc ... the article makes it sound like the browser is optimized for text but isn't it really the server that's ren

I've recently switched from Markdown to ASCIIDoc ... the article makes it sound like the browser is optimized for text but isn't it really the server that's rendering the text that's sent? In this case, I like the idea of minimal styling mostly because my eyes are getting old but as others have stated, why isn't this specification a small subset of the existing internet?