If they left that swappable infrastructure unattended in most cities in the U.S. it wouldn't take long before someone destroyed it, stole all of the batteries and then tried to sell them on eBay. Maintaining the battery swapping stations 24/7 would be a major cost unless it could be located in an existing secured facility that was staffed all of the time like a 7/11 or gas station convenience store.
That's exactly where the battery swap stations have been located in Taiwan: gas stations.
The idea is workable as long as you have density and can get past the chicken-egg problem of station-availability leading to scooter sales leading to demand for stations. Before it folded, Scoot was in talks with Gogoro to replace its Genze 2.0 fleet with Gogoro scooters and maintain + operate the stations in San Francisco for both our own swaps and private Gogoro and Yamaha electric scooters using our roving field technicians that had to go all over the city every day to maintain our scooters and garages. It would have been a great idea that could dramatically lower the cost of running a shared electric moped service.