While I agree with this, there are the caveats that both light electric bicycles and heavy analog bicycles exist, and that in many cases the additional mass of the motor and battery may not contribute much to the overall momentum once the mass of cyclist and cargo are factored in.
Note: I commuted by electric bicycle before I switched to working remote, and I have to say that riding a vehicle that tops out at ~30mph when you're slamming the throttle _and_ pedaling as hard as you can on a road with cars and trucks going 45mph (or faster) is a harrowing experience. The few miles where I rode on bicycle paths, though, I capped my speed at 15-20mph (around what a decent cyclist would do) and slowed to 5-10mph when I was approaching foot traffic or other cyclists - and nobody ever batted an eye (except a few people who wanted to know where they could get one, heh).
Or perhaps momentum, which is far higher in motorised vehicles.