Interesting experiment, where some guy formed a crater and its rim companion using electricity, water, and silica.
Reading up on craters, they seem to be formed by explosions of the impact bodies’ immense kinetic energy on the surface of larger bodies (planets), not the mechanical impact of the body itself. That’s the official explanation, anyway, and it explains why craters are roughly circular and not like a line carved into the ground, as the impact bodies don’t hit perpendicular to the ground.
The impact-explosion explanation, though, doesn’t account for why we tend to see craters on the rims of larger craters, or concentric cratering, or hexagonal cratering (note that the large crater in the jar experiment is hexagonal). You’d have to rely on a large chain of weird, impossible coincidences to make the impact-explosion theory work. Maybe not all craters are formed electrically, but the electrically-machined crater model predicts the oddities much more easily than the kinetic explosion, and are easily reproducible on a smaller scale.
It’s also worth noting that electrical discharge events are explosions, so the impact theory gets that much right.