That is a regulatory issue and a name issue. Those are actually motorcycles. In Europe e-bikes are capped at 25 km/h (the electric assistance stops at that speed).

So your problem is (electric) motorcycles that are (legally?) accessible without a motorcycle license and motorcycle equipement. For safety what matters is the speed and the weight of the vehicle, the faster and heavier, the more dangerous.

I am also noting that unlike with SUV accidents, your friend put a lot less people in danger if not only himself.