WebAssembly is like an openly designed Java virtual machine that's intended to run on all systems. You're completely confused. WebAssembly is extremely exciting and I believe it'll soon be the thing in the tech industry. With Wasm you can write one app and run it in the following platforms TODAY:

1. Desktop: Linux + Windows + OSX

2. Browsers: Chrome + Firefox

3. Phone: Android (no iOS)

4. Embedded

it's absolutely amazing. The biggest problem nowadays is packaging and various runtime things, but what I listed above 100% works, you just need to do the work to package it in N different platforms. How is this not appealing?

Imagine you write Google Sheets, it works on your browser, on OSX, on Linux, on Windows and on Android. It's the same binary.