Also see https://michaldrobot.com/2014/04/01/gcn-execution-patterns-i...

A bit of an older article but still very relevant.

I've found with webGL2 you can also skip the whole upload/binding of the buffer and just emit the vertexes/coordinates from the vertex shader as well.

Less of an impact than cutting it down, but if you're just trying to get a a fragment going, why not use the least amount of data and CPU-> GPU upload possible.