I figured this might be interesting to some folks on the forums: I updated an old script I had demonstrating how to make a command line tool with a SwiftUI UI. It is now much easier with the new SwiftUI App Lifecycle support (its a whopping 20 lines shorter)!
If you create an executable script from the following gist (chmod +x <path-to-script>), you can invoke it like a script to see it in action (this requires your command line tools to be set to Xcode 12).
No, because command line scripts treat the body of the script as if it were “main.swift”, so synthesizing a main.swift using the annotation creates a conflict. Either way, it would just be one line of code versus another, so not a ton of utility.
That said, we are, benefitting indirectly from the introduction of the @main attribute, because it encouraged the simplification of the architecture to just having a static main method rather than @NSApplicationMain doing a bunch of magic.