Just this week in Vantaa, Finland three 12-year-old girls piled onto one of those electric scooters you subscribe to with an app and proceeded to get run over by a car at a crossing, killing one of them
The app is supposed to have an age restriction but it's easy to bypass and you're not supposed to have more than one person riding on one, which people routinely ignore
I hate seeing kids and teens speeding around dangerously on those fucking things and then just leaving them laying around on high-traffic bike routes because they don't give a shit since they treat the scooters as completely disposable
Fucking awful bazinga-brained Silicon Valley-ass idea and business model. Actually, there are also bikes you can use with an app but curiously you don't see kids doing reckless shit with those, almost as if electric scooters were uniquely terrible 
Okay seems like the actually dangerous thing in your story was the car??? Kids should be able to do dumb shit without having to worry about being turned into tomato paste.
They shouldn't have access to motor vehicles to do their dumb shit on
Your complaints are indistinguishable from those levied against bikes. Multiple kids have been piling onto the same bike since forever. It's even made its way into Boomer/Xer nostalgia bait about riding around your neighborhood with your first love on your handlebars. I guarantee you the death rate is higher for kids on bikes than for scooters. I say this as somebody who loves being a cyclist and uses a bike for literally all of their chores.
Bikes aren't motor vehicles