Amendment: Perhaps it's debatable what "substantive benefit" would be, but writing the whole app in it is a huge benefit if you really want to do that. That is to say, for years people wanted to write Web UI stuff in various languages, this also allows for that.
So while the concrete performance boost may not be meaningful in writing an entire web app in C, Rust, Go, Python or w/e - to the developer happiness the boost may be huge for those devs that want it.
My next app I'm planning on using a Rust WASM DOM framework, and I know there are some in Go as well. This is primarily for developer UX.
One example among many ramping up
As for designers, thank you for finding a much more diplomatic phrasing than the one I was about to write.
And thanks to many, including HN readership, Chrome and Safari are the only browsers that many businesses care about nowadays.
I should just have linked something done in Unity instead.
i.e. Figma said it reduced page load times by a factor of 3, though they were using WASM to replace existing asm.js code.
https://www.figma.com/blog/webassembly-cut-figmas-load-time-...
I've only done web development for a year now and I've seen some cool WebAssembly demos but mostly those are demos of various frameworks (or no framework) reusing random WebAssembly components.
It's cool, but I'm missing from a large web application stance how WebAssembly is supposed to work, specifically when it comes to stuff like you see in some frameworks with state management across components and etc. Is there an example of that?