How easy/practical is it to ship a WASM binary to run on all major platforms?
Numerous native runtimes for webassembly already exist[0], with the current popular choices apparently being Wasmer[1] and Wasmtime[2].
All one would need to do (AFAIK) is ship a client for all major platforms, as is done with Electron (and web browsers themselves, and everything else.)
[0]https://github.com/appcypher/awesome-wasm-runtimes