Funny how a text based website doesn't work without JS.
It's not one of those sites where the content can be easily found in the source of the page either. The latter appears to be, at a cursory inspection, consist of tracking scripts, furthering the irony of this demonstration.
At least a site that calls itself "the TLS" is served via HTTPS...
Don't rely upon it to exist.
Serve up well marked content, CSS that might format it nicely, and JavaScript that allows some types of per-validation to happen client side but only as a means of making a page nicer. The server side should STILL perform all data validation, normalization, and verification (assume someone will craft their own form submission).
Twitch could be done with a native app... the phone versions SHOULD be done with such if they aren't.
As another poster commented, the video aspect can be fulfilled with a number of different methods, and I don't see any technical reason a standard couldn't be followed to allow for arbitrary clients to handle that interaction as well.
As for video streaming, that's not hard at all, especially now that there's a <video> tag.