There is so much to unpack from this study. It also looks at how e-bikes are easier for older riders, keeping them fitter longer. It also reinforces my opinion that the Europeans got it right by limiting speed and power on e-bikes and mandating that they are all pedelecs rather than throttle operated; you don't get much exercise on a motorcycle. That horse is out of the barn as far as the laws in North America go, but that doesn't mean that just because you can buy 750 watts and a throttle that you should. You want a bike with a boost so that you can still get some exercise, but also go farther, faster and easier for a longer, healthier life.
...in general, the study as it was performed is invalid when applied to the American model as I see it demonstrated daily in the state capital of California. Plenty of people cruising along at speed with minimal effort. Which seems to be the point for many users. I just try to stay out of the way and give them plenty of distance.