Exactly. I can't tell you how refreshing that is after 5 years on of Kotlin and Swift. One way to do everything, terse syntax that assumes memory managements, and functional. Amazing stuff.
In practice how is Dart functional? All I see in Flutter is classes all over the place. It's like no-one learned anything from the evolution of React and the decline of Angular.
Mostly because it has first-class functions and that's about it. Future might be used as a monad, but I'm not sure. Currently it has no ADTs, no pattern matching, Java-like immutability, null safety seems to be a special compiler feature rather than an option type or monad.
Right now it's less functional than Java, about as much as JavaScript (though in JS classes are less idiomatic so maybe it's a bit more functional in practice).
Considering what people are asking to add to the language (https://github.com/dart-lang/language/blob/master/working/05...), I wish people would start with a minimal functional language (Caml/SML without the modules, so functions, pattern matching and ADTs mostly) and then add things from there. It's a strong basis for a language, and people are going to ask for that stuff later anyways.