Like you say, downhill it's the same. but on average it's going to be slower because it's speed limited, so it's not fair to say ebikes are faster by any measure.
I'm in New York City. Here you need a special license to ride a motorcycle, but you can ride an ebike with no license. The law here treats them the same as regular pedal bikes. I would judge that they are travelling 50 kph, especially the food delivery services. Most of the delivery guys wear motorcycle helmets. A freind of mine just broke her elbow after her pedal bike hit a car door.