It's absolutely useful in practice. Sometimes the library you need was written in C++, and needs to run performantly and offline. I needed WASM and PWA to make an offline Japanese dictionary: https://birchlabs.co.uk/mecab-web/index.html It uses WASM to do linguistic processing via the C++ library, mecab. It tells you where the spaces should go in a Japanese sentence, and what the dictionary form is of each word (so you can lookup the meaning).