Edit:
To be clear, I'm taking about the unmotorized scooters.
Here in OZ, with mandated cycle helmets we had a drop in catastrophic head injury. Scooters have the same legal burden but it's not enforced well so alongside the arm and leg injury, is the rise/return of catastrophic head injury.
Motors only make it worse. I think there's like an inverse square law speed to survivability for bodyshock. Unpowered? you often walk away. Powered? You, or somebody else, is at serious risk of not walking away, ever.
I will note (as the author) that using the un-motorized kickscooter means traveling at a slower speed than virtually all e-scooters out there on the market. Slower speeds make for safer riding as it is much easier to stop--and over time you get very familiar with terrain and spotting the risks in surface imperfections.
> Please don't use HN primarily for promotion. It's ok to post your own stuff part of the time, but the primary use of the site should be for curiosity.