Typescript is defined to run exactly as the equivalent Javascript you get when all the type declarations are stripped out of the source. There's no benefit in compiling it to WASM unless you had a WASM JS engine (or JS->WASM converter) that executed JS faster than the browser's built-in JS engine (or created WASM binaries that were smaller than compressed minified JS, which seems extra unlikely when you'd have to include a JS runtime). If that existed, browsers would just upgrade to use that internally on all JS.