Looked into this a while back, and this isn't really true[1]. Worst case (6m lifespan) emissions from scooters are twice as bad as a passenger car per passenger-kilometer, and best case comparable to a tram (assuming 2y lifetime). Lifetime was the determining factor. Has anything happened in the last couple of years to increase the average life span of these scooters, to change this scenario? Unless average lifetime is 2 years or more, emissions are nowhere near "low".
A few years back, I talked to an engineering manager at one of the scooter companies and he said that their longest lived scooter at the time was 11 months old. I can't remember what the average was at the time, but it was shockingly low. Something like 3 months. No idea what it is now.
Having worked at one of the big scooter companies, I can say that (when I left in 2021) we had plenty of scooters in service that had been operating for two years or more.
That said, this generation of micromobility has fallen flat. Any solution that's economically viable will need either dedicated infrastructure or self-driving (so you don't need to send a person after each vehicle), not to mention better safeguards to protect the vehicles themselves (vandalism/theft was the #1 cause of vehicle end of life, and even if you can turn a stolen scooter into a brick, $20 of spare parts is still $20 of spare parts to an addict or anybody else who is sufficiently desparate). All of that is to say that the first company to crack that nut will almost certainly need to work in close partnership with city governments--the Uber model will not work.
Glad to hear that they are lasting longer. I probably should have prefaced my comment by saying that this was around the first year that these companies really blew up in LA. (Can't remember when that was.) Vandalism was super high and they were just figuring things out.
Looked into this a while back, and this isn't really true[1]. Worst case (6m lifespan) emissions from scooters are twice as bad as a passenger car per passenger-kilometer, and best case comparable to a tram (assuming 2y lifetime). Lifetime was the determining factor. Has anything happened in the last couple of years to increase the average life span of these scooters, to change this scenario? Unless average lifetime is 2 years or more, emissions are nowhere near "low".
[1]: https://sci-hub.se/10.1109/e-tems46250.2020.9111817 (In particular fig. 3 and 5).