Comment by flohofwoe

> "redraw everything the whole frame" and "don't do any diffing" sound insane in this regard.

You need to consider that a web browser with its millions of lines of code in the DOM and rendering engine is pretty much the worst case for "redrawing a complex UI each frame", especially since the DOM had been designed for mostly static 'documents' and not highly dynamic graphical UIs.

Add React on top and the whole contraption might still be busy with figuring out what has changed and needs to be redrawn at the time an immediate mode UI sitting directly on top of a 3D API is already done rendering the entire UI from scratch.

A native immediate mode UI will easily be several hundred times less code (for instance Dear ImGui is currently just under 50kloc 'orthodox C++').