10 mph is more than enough to injure someone on collision, especially if that person is frail. Average human walking speed is 3mph. Runners average 10mph, but a running human has a lot more control over their momentum than someone in a vehicle, because they are expending their own energy to move, rather than using an external propulsion system, and they aren't on wheels.

> Talking about such, is there any data on accidents caused by e-scooters? (percentage wise e.g. vs bikes)

I don't know, but except for small children, bikes are already banned on most sidewalks in cities with a lot of foot traffic. Some adults choose to ignore those rules, but that's a different issue.