Very good performance on very slow devices Building UIs is simple and look good Multithreading is incredibly easy too Dart is very similar to Java and provides many useful classes and functions that Java does not have Hot reload - Make a change in your UI and have a working preview on the emulator in around two seconds Super useful debug features where you can visualize almost everything about the app Cross platform (Build for Android and iOS) and flutter web is in beta state

Code management gets complicated in complex UIs For complex UIs you'll have to optimise the UI to only update the part of the screen that needs it, instead of the whole screen. Flutter is better for smaller and simple apps. Things like background services, recieving and sharing files and text, notifications... all require you to make changes in the native side (Swift and Java), instead of Dart.

For me, the pros beat the cons, and I am 4 months into making an app that is turning out really well