Because the vernacular definition of 'vehicle' in this context does not include crutches, wheelchairs, kites, or slippers.

It might include a powered mobility scooter.

Kites, toy cars and toy boats are toys (to me).

Drones and balloons I would say are in the park, whereas aircraft (at normal altitudes) I would say are not. Unfortunately: I'd like more parks to have a protected square inch of silence.

0. https://en.wikipedia.org/wiki/One_Square_Inch_of_Silence 1. https://onesquareinch.org/

What’s the difference between a powered mobility scooter and a modern wheelchair?

Weight and top speed that most of their occupants reach, although I haven't looked closely at a lot of 'modern wheelchairs', so I may be off the mark.

So no effective difference, then.

There's be a pretty big difference for someone that they ran into, just like I'd much rather be ran over by a golf cart, than by a Honda Civic.