Vector3.MoveTowards becomes instant in while loop or freezes unity

   bool inputMove;
   bool canReturn;
 
   float mainSpeed = 16
 
 
   void Update()
     {
         if (Input.anyKeyDown)
         {
             if (Input.GetKey(KeyCode.Escape))
             {
                 // da
             }
             else
             {
                 if (!inputMove)
                 {
                     inputMove = true;
                 }
             }
         }
 
         while (inputMove)
         {
             print("inputMove = true");
             float step = mainSpeed * Time.deltaTime;
             transform.position = Vector3.MoveTowards(transform.position, new Vector3(0f, 2.4f, 0f), step);
             if (transform.position == new Vector3(0f, 2.4f, 0f))
             {
                 inputMove = false;
                 canReturn = true;
             }
         }
 
         while (canReturn)
         {
             print("canReturn = true");
             float step = mainSpeed * Time.deltaTime;
             transform.position = Vector3.MoveTowards(transform.position, new Vector3(0f, 4.4f, 0f), step);
             if (transform.position == new Vector3(0f, 4.4f, 0f))
             {
                 canReturn = false;
             }
         }
     }

at 16 and 1.6 for mainSpeed it just moves the game object instantly and when I try lower values for mainSpeed it starts freezes a bit and then the game object doesn't move and when I get to 0.016 and lower for mainSpeed unity freezes completely