One of the most significant deterrents to cycling has been the danger involved with being mixed in with automobiles that are easily able to injure and kill a cyclist. The biggest gains in increasing bicycle use has been by creating bike lanes for all ages and abilities that are completely separated from traffic with physical barriers. These are safe spaces for bicycle users and all people can feel comfortable riding on them, whether they're young and fit, elderly or if they're riding with their young child that is just learning.
With the advent of fast moving electric bicycles, suddenly these all ages and abilities bike lanes may not be such safe spaces any more and this could discourage people from cycling. People may not want to take their young child out cycling if there are food couriers zooming by at speeds that a normal bicycle wouldn't be capable of.