These electric scooters travel at speeds that exceed that of an average cyclist. They are not pedestrian friendly and they have no place on sidewalks. Usually you see them only on roads, bike paths or shared spaces where cars and pedestrians are both allowed, though. At least in vienna.

In bike-friendly European cities like Amsterdam and many German cities you generally have dedicated biking lanes which makes this a non-issue. On bike-unfriendly cities like Paris the sidewalks are often so crowded and filled with obstacles that merely walking fast can be challenging at times.

I can believe that it works great in American cities with very large roads and mostly deserted sidewalks but that wouldn't translate well everywhere I think.