I disagree. There has never been a better markup language. HTML allows precise control of atomic elements that make up a component. It has been the best thing for accessibility we ever came up with.
I can imagine no better way for readability and accessibility than a text-first representation of content, which is what HTML is. I will even argue that having the modern web emerge from a text-content first approach is the best thing that could have happened to us.
All other content representation infrastructures that weren't text first, like java applets or flash died because they were no match for HTML.
Agreed! Markup-as-content-backbone is one of many things HTML/CSS do extremely well, and I agree not building around something like this was a major weakness of Flash.
Silverlight sought to do this with XAML, but it had other problems (required a plugin right as plugins were on their way out; CLR was a huge dependency; too locked down and proprietary under Ballmer leadership)
Can you imagine a text-first content representation, which is visually editable with the UX of a vector design tool? This is the rabbit hole that drives our work on Pax.