I ride an e-bike. After I got it, my physical shape deteriorated rapidly as my primary means of exercise was reduced. Now I make a conscious effort to turn off the assist once in a while to get some exercise.
Indeed. But you're making a point that pivots from the point the OP made and I replied to.
The OP suggested that because they witnessed people utilising these devices, that these devices inherently exist to support our (as a group) sedentary lifestyle. That argument is weak simply because it ignores any other value these devices could provide to a user (like enjoyment, faster movement, etc).
It is essentially taking a new concept and looking at it from the most negative viewpoint imaginable, while ignoring the fact that these electronic alternatives offer mountains of improvements to the user and society at large.
Plus if we want to talk about sedentary, what is more sedentary than sitting in a car or on public transport? Certainly not a device where you have to shift your weight around to maneuver it.
I guess it depends on how you ride it and what kind of exercise. For me, I found that I was doing more endurance training, as I would cycle 100+km, which I never did before I got the motor. However, I lost a lot of strength training as I no longer really had to fight with the numerous steep hills around here, and I found that I could no longer bike them after a month on the motor.
So now I occasionally turn off the motor before a really nasty hill just to force myself to really push it once in a while.
It could be, I don't know, people find them fun and like to have fun? I know, crazy, but just consider it.