Source of performance issues compared to other solutions

[pot2mayo]

Hi

I evaluating several 3D rendering solution for a 3D game in react native.
Expo-three is one of them, along with Babylon.js React Native and Unity WebGL build in a RN webview.

I noticed that both Babylon.js React Native and Expo-three have significantly lower performance (about half the framerate) compared to a native Unity build using the same scene.

I understand that react native adds some overhead for the scene setup and asset processing, but since all graphics APIs are backed up by purely native GL calls under the hood, I don't understand such difference in performance for the rendering itself.

Could you provide some hints on why we have such performance hit for react native solutions?

Thanks a lot!