I disagree. You can very often just drop in webgl2d[0] into your Canvas based app and in most browsers see a performance boost, often a significant one.
WebGL-2D isn't even close to being a "drop in" replacement for Canvas 2D. It's still nifty though.
A closer alternative is https://github.com/phoboslab/Ejecta. That's using OpenGL ES 2, not WebGL, so there'd be some work to get it running with WebGL.
[0]https://github.com/gameclosure/webgl-2d