That option is not sustainable. There should be real penalties for abusing pedestrian space. The current situation is untenable.
While I totally agree that they shouldn't be wizzing around in pedestrian spaces, what is it that makes them worse in principle than cyclists who can also do that?
The rental ones have a 5mph(?) limit when they detect they're on a pavement btw.
I enjoy them once in a while when I'm somewhere with a rental scheme but would only ride them on a road or perhaps crossing a pedestrianised city centre type place where there was no alternative. It's up to the user not to be obnoxious. Please don't throw the baby out with the bathwater.
Bare in mind the escooter riders you currently see are (unless they are on a rental scheme) by definition scofflaws!
Getting back to the subject of the thread, the ebike assistance limit is crazy. I'd have it up to a level you need a helmet if you come off - maybe 30mph? Scooter limit of 15 is probably about right with UK potholes.... don't think I'd fancy hitting one at 20mph on an escooter, at least without a helmet which I really don't want to be compelled to wear)
(I'm a big fan of removing speed limits in general though where appropriate - I want HGVs to be able to do 80mph, Coaches/Vans 100mph, and cars/bikes entirely derestricted on motorways. We're really pathetic about this stuff)