TIL that WebGL treats IBOs and VBOs differently from actual GL, supposedly because it makes security validation easier.

That means you can't `glBindBuffer` to some target and fill in the data, because when you later `glBindBuffer` to `GL_ELEMENT_ARRAY_BUFFER` you'll get 0x0502 GL_INVALID_OPERATION.

One problem though. This is not documented *anywhere*, either in WebGL `.bindBuffer()` or in the GL ES `glBindBuffer` :V