I have successfully used Haxe in isolated cases to build games for WebGL and Canvas. I think transpilers are most useful when you rarely want to reach outside of your own code, or you only need to rely on a few key libraries that are known to be well supported within the ecosystem of your transpiler language. I also struggle without a static compiler, so for my case it makes sense to use a transpiler, even with all of its pitfalls.

If there is one thing however that I have learned from using transpilers it is that externs as a whole are a huge waste of time, as it can be difficult to determine their quality upfront. If you are building a Node backend or SPA, you are going to need to rely heavily on existing libraries and will probably find yourself constantly hitting walls while you try to swim against the current of the ecosystem if you try to use a transpiler.