I think it was a combination of things. The city didn't ban them outright in response to the initial problems, in fact they set up no-go and slow zones within which the scooter companies have to disable or slow down the scooters.
Some kids that ran into a baby stroller (no one was hurt) were made a huge example of in the local news, the family fined and shamed to hell and back. The problem is the people, not the vehicles.
The city was already built for mixed modes of travel, so there were already bicycle "highways" that are perfectly suited for these. As my city was already extremely favourable to multiple layered transit systems, instead of getting rid of a new one, a lot of work was put into solving the problems around it. And traffic separation has only gotten better in the years since.
I also think people here were just more courteous around something like this to start with. A city-run public rental bike system had been a thing for a couple of years already, so the concept was somewhat familiar. Though they aren't electric, and have to be parked at special racks.
The most recent development is that some car parking is being converted into scooter parking around common destinations, and the scooter companies now give you a discount for parking in them, alleviating the big disorganised piles of scooters around transit hubs, supermarkets, etc.
The rental fees have gone up to much more realistic amounts, so people don't use them every chance they get anymore. And when they do they try to get where they are going in a timely manner so as to not waste money on a minute more than they have to.
And I think more are committing to using them long term using the monthly passes. I've been seeing more and more people carrying helmets, for when they use a rental scooter. They've legit become a utility, integrated into people's routines, instead of sporadic entertainment for drunken idiots.
At least one company has instituted a system where you can report badly parked scooters, which on repeat offenses apparently results in some kind of consequences for the person who last used it.
During the second summer the city limited their speed to 15kph across the board for a month, IIRC, which I bet took the fun out of them for people joyriding them. There was also a "curfew" for a while where they would stop working after 9pm, because people were using them to ride home while drunk.
The limit is back up to 20kph, I'm on my fourth summer of skateboarding, and no-one seems to be a dick about it anymore. Electric personal vehicles are just one of the things you see in the city now, and they are used by everyone. It's been especially nice to see more of the elderly out and about on pedal assist bikes.
But introducing them definitely came with some bumps.
