Do EV's have gearboxes?
But a lot of non-car electric vehicles (maybe the majority) use hub motors, where the wheel's angular velocity is the same as the motor's.
That's not the whole story, though, as a more illustrative number is the ratio between wheel radius and the motor's air gap radius, multiplied by whatever reduction gearing is used. I don't think there's a name for this concept, but you could borrow "gain ratio" from bicycles (https://sheldonbrown.com/gain.html).
For a hub motor the wheel pretty much has to be bigger than the motor for ground clearance (unless you're a monorail or something), so the gain ratio is less than one (maybe 0.5 for a skateboard and 0.25 for an ebike).
And practical wheel speeds tend to be a lot lower than even an inexpensive motor's top speed (not surprisingly, by about a 10:1 ratio).
Bottom line is a hub motor tends to be ~10 times larger than it would need to be on a peak torque basis, so fitting more torque into a smaller package (even at the expense of top speed) is a win. On the other hand solving the peak torque issue doesn't magically solve other issues that might crop up as you downsize (e.g. heat).
https://en.wikipedia.org/wiki/Tesla_Roadster_(2008)#Transmis...
The Koenigsegg hybrid (so not strictly an EV, but can be operated as a pure EV) famously don't have a gearbox but a single, fixed reduction gear. There is a hydraulic coupling for the electrical motors to allow slow speeds. At higher speeds the coupling is mechanically locked to directly connect all engines to the wheels.
As mentioned, Taycan and the preprod Roadster are exceptions, and those are also the two exceptions I know.