Comment by robocat

Pick a subset aimed directly at accessibility.

The least-needed features are often accessibility nightmares (e.g. animation - although usually not semantic).

The accessible subset could then be government standardized and used as a legal hammer against over-complex HTML sites.

For a while search engines helped because they encouraged sites to focus on being more informative (html DOCUMENTS).

I think web applications are a huge improvement over Windows applications, however dynamic HTML is a nightmare. Old school forms were usable.

(edited to improve) Disclosure: wrote a js framework and SPA mid 00's (so I've been more on the problem side than the solution side).