We already tried JVM in browsers, remember java applets? I sure remember the security and compatibility problems :)
WASM has been designed from the ground up with portability, security, and stability in mind. It is also a lower target than JVM bytecode, which makes it more suitable to represent languages like rust and go. It has also been designed to take advantage of the sandboxed JIT engines that browsers already have for running javascript. Additionally, WASM is an open standard that anyone can contribute to, which is something that is greatly valued on the web.
We already tried JVM in browsers, remember java applets? I sure remember the security and compatibility problems :)
Actually, we didn't really try JVM in the browser. We tried it as a plug-in like Flash. The JVM didn't have access to the DOM like Javascript and WASM will have.
So, none of them out-of-the-box like Javascript. Given, it didn't really work as far out as 2005[1] which is 10 years after Javascript was introduced, I stand by my original statement.
remember them? Some of us still have the unfortunate pleasure of using them. (Worse: the IT desktop folks have to support a very specific outdated version of IE to keep it functional. I remember hearing that's how a new vendor's "solution" would be delivered, and the facepalm I did at the time. The look on desktop support's face was a bit more pale and filled with dread.)
WASM has been designed from the ground up with portability, security, and stability in mind. It is also a lower target than JVM bytecode, which makes it more suitable to represent languages like rust and go. It has also been designed to take advantage of the sandboxed JIT engines that browsers already have for running javascript. Additionally, WASM is an open standard that anyone can contribute to, which is something that is greatly valued on the web.