This is not what I see; these things go-go-go, even if the rider puts out no effort. I see people going over 40 km/h on e-bikes while basically just barely pretending to pedal.
This is not true. Have you ever used one? I own one and cycle with it daily.
It takes less effort to cycle, and so you can get faster speeds easier - my Vanmook would get it 30kmph with medium effort effort on flat roads, but then i can coast on that for a bit as it slows down (its not maintaining this speed through a motor). But you still have to cycle - it's not a motorbike.