Those JavaScript cross-platform solutions are opaque boxes that run basically their own operating system within an operating system. This comes at a penalty of

Those JavaScript cross-platform solutions are opaque boxes that run basically their own operating system within an operating system. This comes at a penalty of a non-standard UX and higher than usual CPU usage and memory usage. But after they tackled that hurdle (like Visual Studio Code, excellent work), they still lack a lot of platform standard goodies like Accessibility and AppleScript. I prefer solutions like Xamarin / Mono where you can have a Cocoa UI coupled with C# or F# based dll's. Let's be honest, as long as you have a good way of maintaining a good state in your app for example by already using ViewModels that did most of the heavy lifting like formatting strings, having the state in a state machine and so on, getting the UI to work as required is just an exercise of filling in the colors between the lines. Barely anyone would notice they were using a Xamarin based solution on a Mac, while the JS based applications are immediately really obvious to the trained eye.