On a recumbent bike your body is in a horizontal plane and your feet first. Your weight and center of gravity is lower and between the wheels. In the same circumstances you will likely fall over onto your side. In fact some recumbent riders, including myself, have been able to step off in an accident rather than becoming entangled with a conventional bike. Because they are different.
Conventional bikes attempt to configure the body around the bike.
Recumbents configure the bike around the body, laws of efficiency and aerodynamics. This is also why designs differ so much from recumbent to recumbent. Consider that the conventional bicycling position evolved from an 1800 s contraption with a beam of wood, two carriage wheels, and a handlebar. This position really had nothing to do with efficiency or comfort. Amazingly most recumbents take very little balance and this is the toughest part for a new rider.