I was waiting for someone to mention Xamarin. :D
I haven't worked with the platform for 2 to 3 years. In my old job we had massive problems at the end hence we switched to native (we were an agency).
Problems we had:
* Deploying to devices was painfully slow compared to native stack.
* We all had Macs and the tooling (Visual Studio for Mac/MonoDevelop) was pretty bad compared to Android Studio.
* Wrapping 3rd party native libs was a pain, if not impossible. Especially in a stressful agency environment.
When we heard about the acquisition of Xamarin by Microsoft I was hopeful things would change to the better. But month later they rebranded MonoDevelop and focused on integrating Azure.
Did it get any better?