Most ebikes you have to pedal to make them go. Some just push the throttle, but most are motor assist but if you don't pedal you don't go. As such most ebikes give the same fitness benefit but let you go faster (read farther). My ebike almost forces me to work harder than the regular bike as because it is heavy it feels like it doesn't coast as nice as the regular bike, and so I'm pedaling more. (part of this is probably I'm going faster and so wind resistance is lowing me down more - but to me it feels like I have to work harder to make the ebike work, in return I go farther on it)
> As such most ebikes give the same fitness benefit but let you go faster
This is simply not true. A pedal-assist bike will go faster with the same amount of W put into the pedals, yes. But will people put in the same amount of W if 60 % will get you to your "target speed"? I doubt it. And then you get less health benefits for the same distance traveled.
On my 8 kilometer commute I average 150 W. Not because I use it as exercise. That's just where I find my comfortable level of output. Every time I've ridden on ebikes I've put in much, much less effort. I'd be surprised if I put in even a third of the energy. That's great if you just need a mode of transport. Bikes are practical, efficient, and planning for them improves cities. Even ignoring the potential health benefits. But claiming that a pedalassist bike gives the same fitness benefits just doesn't pass the smell test.
I can only state for myself that I'm putting more effort in (since I can feel the bike slow down more when I don't). Plus the ebike allows trips that because of distance I wouldn't use the regular bike for.