In short, when compiling to Wasm, you are building a binary that is agnostic of the operating system and CPU architecture it is going to run on, so it can be executed in lots of very different places (microcontrollers, Raspbery Pis, in the cloud).
You can also use several VERY different programming languages, and interoperate between them (write a component in Rust, import it in a new component in JavaScript, and use those two from C# — this is an example for how the component model will (hopefully soon) enable cross-langauge interop in WebAssembly).
Among other benefits, the compact binary format (which makes it easy to distribute modules), the isolation sandbox, common compilation target.
Sure, I suppose that's one way to put it. It has a lot of real, practical benefits over the JVM though (locked down by default, small surface area, simpler, buy in from major platforms, compilation target for multiple major languages), and this feels like a dismissal you could put on anything that follows in the footsteps of something else. One could dismiss Rust as hipster C++, but that wouldn't really engage with the issues of compile-time memory safety or concurrency or ADTs. Or JSON as the hipster XML! These are all true in a sense, but it doesn't address the actual advantages and disadvantages (both of which exist for all of these examples).
Your intuition is mostly correct. Before anything, I strongly suggest you read this article on server-side WebAssembly — https://hacks.mozilla.org/2019/11/announcing-the-bytecode-al...
In short, when compiling to Wasm, you are building a binary that is agnostic of the operating system and CPU architecture it is going to run on, so it can be executed in lots of very different places (microcontrollers, Raspbery Pis, in the cloud). You can also use several VERY different programming languages, and interoperate between them (write a component in Rust, import it in a new component in JavaScript, and use those two from C# — this is an example for how the component model will (hopefully soon) enable cross-langauge interop in WebAssembly).
Among other benefits, the compact binary format (which makes it easy to distribute modules), the isolation sandbox, common compilation target.
Hope this is helpful!