These aren't my needs particularly. They are just canvas' main good reason for existing, as every other use case is better covered by webgl and/or CSS. Canvas is the Direct2D of the web and development of the API should focus on its unique strength - namely, on being a straightforward high level API for performant rendering of 2D primitives. No one needs garbage API clutter like rounded rectangles. What we need is performance improvements because performance improvements are not a helper function anyone can write themselves in ten minutes.