Why we use digital circuits instead of analog circuits
There are many reasons. The primary advantage is ease with digital signals compared with analog signals that are regenerated. The shape of the waveform is affected by two mechanisms:
1) As all transmission lines and circuits have some noni deal frequency transfer function, there is a distorting effect on the ideal pulse
2) Unwanted electrical noise or other interference further distorts the pulse waveform.
Digital circuits are less subject to distortion and interference compared to analog circuits as binary digital circuits operates in one of the two states-on or off. So, the disturbance must be large enough to change the circuit from one state to another. Also, greater precision is another advantage of this circuit.
Thus, digital circuits are more used than analog circuits.