(May have to reload a couple of times before it works properly!)
p5js also has WebGL support, so I did try to also make a cube here today. And this time, it did not take that long time and much less code. The code comes in under 2Kb while the WebGPU and WebGL were together more than 13Kb. But I did not have the same control. I did not find any way to coloring the vertices in the cube. I probably have to make one from scratch. And I did not find any way to crop the video either. But there is support for webGL shaders. So I think I will also manage to reproduce the cube here, but not out of the box.