I bailed at 8mph on an electric longboard and broke my elbow, severely sprained my shoulder and wrist. I even lost some rotation and dexterity in my hand. It's one of those my arm is never going to be the same type injuries. I was 40 but skated and bmxed into my mid-20s and still felt pretty comfortable with my abilities on the ground (gave up on ramps long ago). I knew this was a risk given the speeds and even got an "off road" model (bigger wheels) to help make pebbles and such a non-issue. Even still, concrete is not flat, you'll eventually come across a missing cobblestone, etc. IMO it's a matter of when not if you'll take a spill.
That said, I think the electric unicycles are much more dangerous. But at least they make it clear that it's not a toy. I passed on the Onewheel because of the random ejection complains I've seen online (which is likely fueling this regulation as it's been known for several years now). While wrecking was not fun, at least I did it to myself. I'd be really upset if I felt like the board did it to me.
That said, I think the electric unicycles are much more dangerous. But at least they make it clear that it's not a toy. I passed on the Onewheel because of the random ejection complains I've seen online (which is likely fueling this regulation as it's been known for several years now). While wrecking was not fun, at least I did it to myself. I'd be really upset if I felt like the board did it to me.