UniChris

On the contrary, my conclusions come specifically from having ridden them. They're cool, but have little actual utility outside some interesting niches like a camera platform.

Not really, they're quite heavy to lug around when done riding, and especially on and off trains or worse busses, up stairs, etc. They especially have the problem of having a large mass of hub motor and battery enclosed in a bulky housing dictated by the tire, so they don't carry as well as the same weight in friendlier shape that hangs closer to the body would. And making the wheel smaller, which I also tried, leads to a poor ride quality.

Electric last mile transport is a decent idea, but a minimal little folding-handle scooter is probably the most practical form - once you stop pedaling a bike form factor is indeed unnecessarily large.

In the long run, last mile is also a social and urban planning problem as much as an individual one. Making cities bike friendly is already challenging enough given that only a fraction of the population could see themselves biking. If there's going to be an electric last mile option that most people on the street could see themselves trying, and thus one that could potentially come to be fully integrated into city design, I expect it's going to be the scooters, more than pedal assist bikes.

I didn't say they couldn't be fast, I said you do not want to ride one faster than you can run. Because, as you point out, it doesn't take much to make you fall - and if you do, you want to be moving at a speed at which you can instantly start sprinting, so that you don't actually go down on the pavement.