The problem with the government’s trials is that being rental scooters they are being abused. They are often ridden by people with little or no experience, possibly underage (although I thought you had to have a driving licence to hire them). Private users are more likely to look after them and not ride them like twats. The government should trial with privately owned scooters with the same rules (15.5-mph maximum speed). The problem at the moment, is privately owned scooters are not legal in public areas so they can't be insured. There are plenty around and some can travel at 50-mph. If they were legalised, there would be rules about capping the maximum speed in the same way that e-bikes are. At the moment a 50-mph+ e scooter is just as illegal as one that is limited to 12.5-mph.
They are the future of urban travel IMO. I do not believe they are any threat to cycling as some of the posts on this thread appear to infer. I had a go on a friend's e-scooter and it was so much fun I bought my own. It does not replace any of my cycling. I use cycling for exercise which the scooter is clearly not. I bought the scooter for fun but I find it useful for short journeys that I would otherwise use the car, such as shopping and visiting friends and family. I could walk of course, which would be exercise, but I'm often short of time. The scooter is convenient in that it folds to the size and weight of a small bag of golf clubs. There are places locally to me where there is no space to lock a bike to, and parking a car is completely out of the question.
Yes they are illegal (privately owned scooters) but so is riding a bike without reflective pedals, and I do that as well!