API Plumbing: The "Hello Triangle"

Immediate Mode GUI
Canvas 2D

Direct CPU drawing commands. No pipeline.

The Scene Graph
THREE.js

Forced to use 3D abstractions for a 2D shape.

The State Machine
WebGL 1.0

Bind buffers, set global state, draw.

The Explicit Pipeline
WebGPU

Pre-baked Pipeline State Objects (PSOs).