It has become very clear over the past several years that smart client software development is largely focused on the browser rather than old-style operating systems like Windows, iOS, Android, etc.
In the past, building smart client apps could be done in many different programming languages, leveraging many different UI frameworks, networking frameworks, etc. But prior to WebAssembly smart client apps targeting the browser could use exactly one language: JavaScript. And only frameworks that could be built in, or supported by, JavaScript.
This was extremely limiting when compared to the rich variety that existed before the browser became the only viable smart client development target.
WebAssembly restores the ability to use many different languages, and thus many different types of framework, for smart client development that targets the now-dominant browser platform. It frees us from the hegemony/monoculture of JavaScript, and should enable substantial innovation and advancement in terms of smart client development going forward.
In short, all the benefits of browser-based deployment and cross-platform app development remain intact, and now we can also enjoy the power of the multi-language, multi-framework flexibility many of us enjoyed prior to the browser (and thus JavaScript) becoming “the only game in town”.