Object Falls from Moving Platform

Its been more than two hours I have been searching and experimenting to make my object move with the moving platform ....

Here's the Code that is attached to moving platform. but still the object does not move along with the moving platform rather falls.

     public GameObject platform;
         public GameObject player;
         void OnCollisionEnter(Collision hit)
             {
                 
                 if (hit.gameObject.tag == "player") {
                 player.transform.parent = platform.transform;
                         }
                 }
         
         void OnCollisionExit(Collision hit)
 {
    
      player.transform.parent = null;
         }

And here's an other script attached to platform for moving.

 public Vector3 pointB;
     // Use this for initialization
     IEnumerator Start () {
     
         var pointA = transform.position;
 
         while (true) {
 
             yield return StartCoroutine(MoveObject(transform, pointA, pointB, 3.0f));
             yield return StartCoroutine(MoveObject(transform, pointB, pointA, 3.0f));
         }
 
     }
 
     IEnumerator MoveObject(Transform thisTransform, Vector3 startPos, Vector3 endPos, float time)
     {
         float i = 0.0f;
         float rate = 1.0f / time;
 
         while (i < 1.0f) {
             i += Time.deltaTime * rate;
             thisTransform.position = Vector3.Lerp(startPos, endPos, i);
             yield return null;
 
         }