An e-bike is pedal assist, you don't pedal, you don't move. The legal limit for pedal assist in the UK is currently 25 KPH that is just 15 mph.
I can ride my non e pedal cycle at over 25 mph so the speed is not the issue.
You don't need a license because it is classed as a bicycle, remove that speed limit or the pedal assist and it requires a license. An e-scooter presumably is 100% e power and does not need you to 'scoot'?
As far as training is required, some people could do with it but as it is a bicycle it is not required, I have been riding bikes for almost 60 years and never had a days training.
Car drivers have plenty of training and look how crap and dangerous many of them are, so not sure as it would help.