Some of them. The downsides of docks it doesn't have:

* You can mix scooters and bikes in the same place

* You can put vehicles from different companies in the same place

* Lower maintenance costs so (hopefully) would be possible to make them more ubiquitous than docks

* If there's an overflowing number of scooters in a spot, you still have the option of jutting a bit into the sidewalk. Even if you never actually need to do that, knowing that it's an option will probably encourage more use. In the past I've avoided docked bike rentals because my destination only had 2 or 3 spaces left in the docks. Even though I probably would've been able to park, that low level of anxiety someone else in this thread mentioned was enough to convince me to change my plans.