why is encapsulation important in oop code example

Example: oop encapsulation example

#include<iostream>
using namespace std;
class ExampleEncap{
private:
   /* Since we have marked these data members private,
    * any entity outside this class cannot access these
    * data members directly, they have to use getter and
    * setter functions.
    */
   int num;
   char ch;
public:
   /* Getter functions to get the value of data members.
    * Since these functions are public, they can be accessed
    * outside the class, thus provide the access to data members
    * through them
    */
   int getNum() const {
      return num;
   }
   char getCh() const {
      return ch;
   }
   /* Setter functions, they are called for assigning the values
    * to the private data members.
    */
   void setNum(int num) {
      this->num = num;
   }
   void setCh(char ch) {
      this->ch = ch;
   }
};
int main(){
   ExampleEncap obj;
   obj.setNum(100);
   obj.setCh('A');
   cout<<obj.getNum()<<endl;
   cout<<obj.getCh()<<endl;
   return 0;
}