Is this basically, how to do GUI's with functional programming. And someone saw the light and it is now the future? People are always getting hung up on the "h

Is this basically, how to do GUI's with functional programming. And someone saw the light and it is now the future? People are always getting hung up on the "how to make a GUI if variables are immutable??". It takes a bit of getting used to, but once over the hump, it seems like GUI's are easier. See typescript, or fabulous, F#, elm, etc...