That's true... but my point was that WebAssembly (including asm.js) now provides what Flash and Java provided previously -- a portal to run non-JS code at near-native speeds.
I think, it could have been Java (or the JVM at least) in place of WebAssembly in browsers already a long time ago, were it a more open standard.
Java itself is a very open standard (OpenJDK, Java language standard, etc.). Openness of the standard wasn't the problem. In fact, it offered a much stronger uniformity of experience no matter what browser you used, unlike web technologies of the time.
The security issues with Java and Flash were the final nail in the coffin, but they had already been fading -- Java due to UX issues and startup lag, Flash due to it simply being a divergent technology from the web itself.