The Vespas and Lambrettas are way bigger and create higher disruption of foot traffic on sidewalks.
With e-scooters gone people will jump on those even more often and consequently leave them on sidewalks even more often.
There is probably a link with them being more expensive, requiring a licence, being registered and the fact that they are not perceived as a nuisance.
I really doubt e-scooters users are going to jump on those in numbers large enough to make a difference.
And yes once you have a "small" 2 wheel vehicle people are gonna ride them on sidewalks and park them on sidewalks.
For all practical purpose the width bubble is the same around the e-scooter and a Vespa, unless you want to be borderline suicidal with the e-scooter.
The only thing that's different is the required athleticism to mount and dismount as well as parking the "Vespa" on the stand.
I reckon maybe they solved the problem of people riding the e-scooter in the opposite sense on the road and the problem of people lifting the e- scooter to transport the e-scooter to areas which are completely closed to vehicles and then riding it there
How much do cities spend on police cars for traffic flow, moving, and even parking violations; but not have similar ratios to enforce more efficient space/energy and safer transportation methods?
In the US, part of our infrastructure underspend is going from full time janitor at a park to a weekly visit by a contractor.