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 
I like the scooters, but I recognize that intermingling them with pedestrians and bikes causes problems. My solution is that cars should be banned from every downtown area and those roads reserved for personal electric vehicles like scooters, ebikes, hoverboards, etc, thus encouraging the use of better urban alternatives to cars but keeping them separated from pedestrians (who should be protected from all vehicles) and bikes (when they have specialized infrastructure that is built for them that the other stuff doesn't work as well on).
Furthermore, speed limits on the e-transport should be enforced based on the tier of safety gear the rider is wearing - so like no helmet up to 5 kph, bike helmet up to 20, and motorcycle helmet at 20+ as an example. You could give each tier its own road lane too by repainting the old car roads with 2-3 e-vehicle lanes per old car lane.
It's a fine enough intermediary solution, but you've just replaced car-centric infrastructure with scooter-centric infrastructure. When people are against cars it's not specifically the "car" part it's the way motorized vehicles make the infrastructure worse for all. Replacing cars with scooters isn't really a good idea.
What you see most other places is that they convert wide roads to large pedestrian crossing and bicycle lanes and then on a longer timespan narrow them down to create small green spaces, resting areas and public utilities like repair stations, kiosks and public toilets.
Roads cannot be completely eliminated from a modern city - too many public transits and emergency services rely on them. I think shrinking every city street down to two car-size lanes that can accommodate a motorcade of firetrucks and ambulances in a big emergency is viable though, and as long as that road's there it makes sense to give people sustainable individual transportation that can take advantage of it. Yes, the city should be designed such that anyone can walk anywhere, and public transit should be widely available, but individual transportation is an awesome luxury and I believe that it is possible to do it sustainably if you don't insist on giving every single person a ton of steel to sit in.
Sure. I thought you were advocating for keeping roads as-is, but just for scooters.