Agree that NativeScript is the most "native" of the JS cross platform tools, since it can use actual native concepts, such as controllers, views, gesture recognizers, etc, whereas things like RN throw the "native" word everywhere, but actually implement everything internally in JS. A small example - a tap gesture in RN is actually implemented using `touchesBegan:` API, which routes input to JS over RN bridge, JS performs the tap logic. Doesn't sound terrible, but consider that the RN bridge is async, so the user experiences a floaty behavior, and if that single JS thread is busy with some business logic, you are dead. Same for animations and interactions. Navigation is a joke, with current and other implementations being JS replicas of the real thing, and the native NavigatorIOS, the one to use actual native iOS concepts, being deprecated.
NativeScript also has a novel idea how to implement multithreading in JS, which is commendable.