Why does society not merely mandate officers to arrest all criminals regardless of how minor the crime is or have them cite all traffic violators?

The fundamental police mission in democratic societies includes five components: Enforcing the Law – Apprehending Offenders – Preventing Crime – Preserving the Peace – Providing the Community with Needed Enforcement Related Services Police discretion refers to the exercise of choice by law enforcement officers as they carryout their mission. Society allows police officers to have such discretion in the decision to investigate, apprehend, cite, patrol, and how to interact with people. It allows for officers to choose (in most circumstances, except for felony crimes) to decide if they will issue a citation, make an arrest, issue a warning, or do nothing. Why does society allow for officers to have discretion in most circumstances the police encounter? What role does discretion play in any of the five components of the mission of policing? Why does society not merely mandate officers to arrest all criminals regardless of how minor the crime is or have them cite all traffic violators? Instructions: Post an example where police officers utilizing discretion to not arrest or cite, can benefit society?