Consider looking at other languages. ClojureScript does a pretty good job at immutability, Elm is great for immutability + strong typing, and PureScript adds in Haskell's advanced type system (typeclasses, HKTs, etc.)
Definitely. ClojureScript is what I usually choose for my own projects, but the reality of the front-end job market is that JavaScript still dominates, so improvements to JavaScript itself will still have a significant impact on the lives of developers everywhere regardless of the existence of other compile-to-JS languages.
When I want to ensure strict immutability, I use an implementation of deepFreeze (https://github.com/jsdf/deep-freeze) that recursively calls Object.freeze() on all child properties. Obviously slower than strict browser support. Does ClojureScript rely on the Clojure compiler to ensure the properties aren't modified or is there some polyfill?
