I used WASI to compile an existing 1990's 8-bit assembler cmdline tool written in C for use in a VSCode extension (https://marketplace.visualstudio.com/items?itemName=floooh.v...) - along with regular browser-based WASM compiled via Emscripten for the embedded emulators.

For this use case the old-school POSIX-style WASI was just perfect and completely hassle-free via the WASI SDK (https://github.com/webassembly/wasi-sdk).

Not sure what to think of all the bells and whistles that were added afterwards (esp the component model), the very first WASI standard was the perfect sweet-spot of simplicity and usefulness. I'm pretty sure I'll never need any of the things that were added afterwards (and I'm going to be slightly pissed when the simple use case - building and running POSIX code - gets more complicated).