Most cars have mechanical and hydraulic systems for these controls. This requires a lot of different parts that can weigh down your car, and all that metal means serious risk of degradation. Drive-by-wire, conversely, is an innovative technology that is used to electronically control your speed, braking, turning, and any other driving command you give your car, which makes for easier handling.
With drive-by-wire, the heavy mechanical parts are replaced with much lighter electrical wires that use sensors to collect information and then transmit the information to the relevant parts of the car. Sensors on the gas pedal, for instance, measure how much pressure you put on the pedal and send the data to the engine management system. This system determines how much fuel is used to accelerate, among other things.
Furthermore, if the electronic system fails, as batteries and electronics aren’t 100% reliable, a mechanical backup system will kick in, solving the drive-by-wire system’s biggest drawback. Plus, fly-by-wire has been used for a long time in planes, so there’s experience and expertise at play. Overall, safety has been considered when it comes to drive-by-wire, and any major issues have been addressed.