Wonder how many of those injuries are on rentals? Veo rental e-bikes are very prevalent around these parts. Have never seen anyone riding them with a helmet. If you own an e-bike and don't wear one, that's on you. But rental ones don't even have a way to provide you with one.
OTOH, most rental e-scooters have a helmet carrier box on the back. It unlocks when you go to pick one up with the app.