While true, only beginners actually use raw GL calls, even in C.
Anyone with experience quickly builds up their mini-engine to handle loading shaders, images, fonts, models, handling everything together for each model, in a mini scene graph way, handling driver and GPU specific bugs...
This is true. From experience I can say that the core experience of using WebGL in JS is very similar to using OpenGL ES in C.
That being said, WebGL and the browser do a little more work for you than the GL API does in C, things you'd otherwise need a helper library for. In particular, there's no shared library or header file hell, context creation is easy, image import is easy, and JS will handle memory allocation for you. It eliminates a lot of the annoying stuff needed to get to writing the actual GL code, though you still have to go through the state machine hell of GL itself :)