With great power comes great responsibility. Whether you take that perspective in Joules, Watts, Newtons, kg.m/s, the conclusions are roughly the same. Drivers needs to be hundreds of times more responsible than cyclists or walkers.
Walking: 5 km/h * 70kg = 97 kgm/s
e-bike: 20 km/h * 90 kg = 500 kgm/s
car: 50 km/h * 2000kg = 28,000 kgm/s
Walking: 5 km/h * 70kg => 875 (although this is a very slow estimate for a walker) (please ignore the non-canonical units)
e-bike: 20 km/h * 90 kg => 18,000 (I think your estimate for ebike mass might be on the low side at 20kg, but whatever)
car: 50 km/h * 2000kg => 2,500,000 (and that's a fairly low speed for cars! Drunk drivers often drive faster than is wise.)
Everything else is a rounding error compared to the energy of a car.
From a harm reduction perspective, Drunk Driving -> Drunk Bicycling feels like it reduces the capacity for damage roughly proportionally to Drunk Bicycling -> Drunk Walking. At a critical level, the speeds you can comfortably achieve are reduced at each step, thereby increasing the amount of reaction time available to avoid an incident, reducing the ramifications of an error, and reducing the amount of damage your body has the capacity to do (by nature of the amount of kinetic energy you are attempting to control).
