Whatever makes you bike is great

Is it as cardio intensive as usual bike? No.

Is it as cardio intensive as sitting on a coach/in a car/on a bus? Also no.

But these are different no.

Whether it’s on a traditional bike or an e-bike, staying active can make a difference for heart health.

yes

Well my watch says yes. The heart rate certainly rises more than sedentary, and usually attains the moderate range on a fitbit or whatever.

I've experimented a bit with this. If you really want to get the heart rate up, you can move to a relatively low gear and do the spin fast and glide thing. But even just riding normally, there is a significant effect. It may feel like the motor is doing all the work, but you're likely pushing more than you think.

I guess if you're talking muscle-building, you could shut off the motor for a stretch? E-bikes are heavy and you will get a good workout in that mode, though the fun level may drop. I do this sometimes on a trail with lots of Pokemon Go stuff. I go to the lowest gear and ride really slow with no motor to hatch those damn eggs already! :p

The obvious answer is "yes", its both.

The similarly obvious and more controversial answer is that if you ride all the same places as your "analog" bike with an ebike you'll get less exercise.

The less obvious and more nuanced answer is that people who ride ebikes generally ride further, and more often, and generally still requires energy to operate, so yes, absolutely.

They are transportation. And they require physical exertion rather than just input so I count that as exercise.

And if the person is unhappy or a jerk they might not even be having a fun ride.

They still require activating various muscles for balance, using the brakes/throttle, etc. I have a medical condition which fatigues my muscles, and I can feel the physical strain of using an ebike or scooter. It's nowhere near like using a traditional one, which I simply can't do, but it is exercise.

I see a lot of ebikes around me that are pure throttle - there are pedals but it is obvious that the rider isn't putting any effort in. However there are also a lot of ebikes where the rider is clearly putting effort in.

A while back, I've wondered if 250w even does much... I recently did a simple setup for a folding bike for someone (very similar to mine, but no motor) and so I got to try it: I didn't get far (it was also a hot/sunny day), so I now know without-a-doubt that 250w is not to be underestimated.

Not to say that I don't get a workout with my ebike, I definitely do in the higher gears (and I mostly stay in PAS 1). Problem for me is these days is I don't ride often enough... I don't really have (m)any places to go, some things are just too far away or I am not equipped for it to be viable.