I enjoyed using Rust/WASM for a web application I made. Once I got the build step figured out, which took a week, the application worked like I wanted right away.

I was trying to build an HTML generator in Rust and got pretty far, but I don't think I'll ever be happy with the API unless I learn some pretty crazy macro stuff, which I don't want. For the latter project, the "innovation tokens" really rings true for me, I spent months on the HTML gen for not much benefit.