> Drag and Drop, animation, AJAX, UI, all have libraries I would prefer. For anything less complicated I can just use what's currently in the platforms. For animation, CSS and class toggles are usually enough. Anything more complicated and there are better libraries for that.

And that's the thing: there are always libraries. There are very few use cases where you want to use DOM APIs directly. They all but sream "use a lib/wrapper/framework".