I had a much lower-powered electric bike for a while. In the UK, if the motor won't push it to faster than 15mph then it counts legally as a push-bike. Then you don't need a licence to ride it and you can use cycle paths etc. (There are some other restrictions, too; do your own research before buying one.)

I found it to be more practical than a plain push-bike for getting to work. The more you pedal the faster you go, so it's still an effort, but that's good from a fitness point of view. I got to work quicker and was less sweaty when I arrived.

I didn't consider it a survival tool because its range was limited to 15 miles or so, and you needed mains power to charge it. A normal push-bike would be better for that. Also, the motor broke in some complex way that was hard to fix; it's not as reliable as a normal push-bike. I don't how it would compare to a motor bike, or a moped; they are probably easier to get repaired because they are more common.