Airplanes can achieve necessary thrust through jet engines or propellor drive, and smaller aircraft typically rely on the use of propellers in order to achieve lift. One of the main reasons that propellor planes are still in widespread commercial use is the fact that they are less expensive to fuel than those planes that are driven by jet engines.
This makes propellor planes a more affordable choice for airlines and passengers alike. Though jet engines are a more modern technological development, propellor-driven aircraft are functional, particularly across the short distances required for regional flights. It's also important to remember that a propellor-powered airplane is just as advanced, if not more advanced, than certain jet-powered aircraft.