Accroding to the results from this paper (page 34) performance of NativeScript is better than React Native, and both are better in performance than Flutter.

The results was quite surprising for me. My expectation was that Flutter will be the best (after Native) followed by React Native.

I found other small benchmarks that shows Flutter is better on CPU-intensive tasks but React Native is better on typical UI side. I didn't found other useful benchmarks about NativeScript.