WebGPU compute shaders performance is expected to be superior to the one you can get with WebGL. This should happen because WebGPU does not have overhead of creating / initializing canvas and writing/reading from framebuffers. The benchmark is built in order to experimentally confirm this assumption and also determine by how much WebGPU performance is superior to WebGL.
yudshj/webgpu-vs-webgl-compute-matrix-multiplication
WebGL vs WebGPU vs JavaScript demo shows the difference in performance when naively multiplying some matrices
JavaScriptNOASSERTION