Aerosol cans of model paint can be used, but of course control is limited, and is also dependant on the physical size of the model. Bear in mind that the spray pattern from aerosols is fairly wide, and the pressure is relatively high. This means that spraying, generally, has to be done further from the surface, which, of course, means the pattern becomes even wider.
On a largish model, say a 1/48th scale 'bomber' sized aircraft, a single colour could possibly be accomplished, given that the model was properly masked where required. The colour itself also has a bearing on the final result, with metallics, for instance, being a bit difficult to spray effectively for a good, scale appearance.
However, many car modellers do use aerosols successfully for spraying an overall colour on the car body, and the physical shape of the model in this instance obviously helps.
The only way to find out if this method is suitable for a particular application is to experiment on a 'scrap' model, but don't expect to be able to achieve great results with a multi-coloured scheme, especially some camouflage patterns for example.
I did try aerosols many years ago, before I got my first airbrush, but gave up and went back to brush painting, which I still do at least some of the time, depending on the job.