I was profiling my Quest 2 game using RenderDoc and noticed that GUITexture.Draw under GUI.Repaint was taking up a third of the render time. What is this and how can I figure out what is causing it?
Do you have many draw calls in UI?
If so, texture atlas those and flatten the hierarchy if possible. Using quads might also help with rendering.
Does the Unity profiler or frame debugger say anything?