These are mostly business issues. If the business problems would be solved, the games would be built, despite any technical limitations of the web platform (which are not much different than limitations on low-end Android mobile devices).

Nobody has figured out so far how to make money with high quality games on the "open web" to get the same return on investment like simple ad-driven 2D games running on closed platforms like Facebook which can technically be cobbled together by 3 dudes in their mom's basemement (exaggerating a bit here of course).

E.g. no matter how you approach it, the Citadel demo wouldn't have led to a web game that would make the same profit relative to the development cost like a simple ad-driven Tetris style game.