This seems like a sensible but odd carveout. The law is essentially legalising e-scooters on shared paths, and bike lanes on roads with no more than 20km/h. The proposition does not allow them on footpaths, which you’d think would be the most relevant place. Personally, I’m surprised they wouldn’t allow them on footpaths but no more than 5 km/h in heavy pedestrian areas (anywhere a car would have to do 40 km/h or less), especially since you could potentially require shared e-scooters to enforce this speed with GPS.
One thing I noticed about them when I was visiting Perth is how silent they are. When people are using them on footpaths, I as a pedestrian had almost no indication that there’s one about to pass from behind unless the rider speaks up. So turning or stopping on footpaths felt quite dangerous. Almost got hit by one when I was trying to walk into a shop and someone whizzed by. Maybe if they’re more common around Sydney I’d learn how to notice them better but that experience scared me a bit.