There are definitely confounding factors - e-bikes are considerably more expensive than pedal bikes (and I've never heard of anyone giving away e-bikes for free), so a different group of people purchase e-bikes. Bikes become a utility while e-bikes are more of a lifestyle choice.
The reasoning of "e-bike riders end up doing more exercise because it is easier" may make sense for casual riders, but anyone who dons lycra or even just thinks of themselves as a "cyclist" would likely not be trying for casual levels of exertion but rather to push themselves pretty hard. I personally will attempt the hardest climbs I can on my bike because of how rewarding they are to finish (and descend, which is honestly where all the fun is!). I will grant, though, enabling e-bike commutes that would be way too tiring on a pedal bike is certainly a big plus for casual/commuter riders.
And of course, I personally enjoy doing something out of purely my own physical power, and so clipping into a lightweight bike and reaching the top of Old La Honda is just beautiful for me. If I wanted the views from the top/the journey and the experience without exerting all that effort, I would drive to the top of Skyline instead (which I have done, often, and genuinely enjoy too! I'm not just ridiculing here).