[luzifer42]

You really need a good reason to choose a non native language (e.g. not JavaScript for the Browser). One reason might be that you target other platforms too (cross-platform). In that case, you are outside of the browser anyway and you need to come up with solutions to these problems. Implementing those in a consistent way across all platforms for your product is not generally a bad idea. The alternative is an inconsistent but native UX for each platform.

[bschwindHN]

Isn't WebAssembly the clear answer here? You can bind to JavaScript so you can still have all that comes with a browser environment, while still being able to use a different language. Performance may not be as good depending on what you're doing, but it's certainly better than reinventing a whole UI framework in a canvas.