I did not love reading the code examples. Call me a lightweight, but I think Swift and Kotlin have a pretty good balance between being verbose enough to read easily, and expressive enough to not need a ton of code. This syntax feels like a step backwards.
The problem with both Swift and Kotlin, is that you must use libraries to draw and handle events, which typically makes it tied to a single OS (Swift only really being used in OSX at present). Kotlin might rely on the very extensive JVM libraries, which are horrendously complicated.
I don't know what you mean by a step backwards. This a batteries-included environment like VB6 and Borland Delphi, but emits to the current web app universe we live in, so it is definitely in the now.
