Eh, oversimplification. AWD systems can and do get used offroad pretty often. They're not quite as good as 4WD in some specific situations, but AWD is still better than 2WD in basically every offroad situation, and it's good enough to get the job done most of the time, for mild offroading. If you're doing serious rock crawling or going through very deep soft sand, mud, or snow, 4WD will likely be better than AWD. But for tackling your average trail or poorly maintained dirt road, AWD will do fine.