Where WebGPU changes the maths

WebGPU is not simply a faster WebGL. The substantive changes are that state is baked into pipeline objects and bind groups ahead of time rather than validated per call, which cuts CPU driver overhead dramatically and raises the draw call ceiling; and that compute shaders exist, so particle simulation, culling and post-processing can run on the GPU without the round trip through textures that WebGL forces.

If your scene is GPU bound on fragment work, WebGPU changes very little: the same shader still runs the same number of times. If you are CPU bound on hundreds of draw calls, or you are simulating things in JavaScript that want to be on the GPU, it changes a great deal. Diagnose first.

For production today the sane shape is a WebGPU renderer with a WebGL fallback, which the major libraries now support behind one switch. Whether the second code path earns its keep depends entirely on whether you have a compute-shaped problem, and most marketing scenes do not.