Why is this simple script causing the multi touch to be so jittery/laggy/breaking?

Hello all,

I have this very simple code that should rotate an object. However when I press on screen and drag either left or right and hold finger on final position, the object continues to rotate but very jitery/laggy/with breaks and sometimes it completely stops and resumes the rotation with the same jitery.

Here is an example scene:

 using System.Collections.Generic;
 using UnityEngine;
  
 public class TestScript : MonoBehaviour
 {
     Dictionary<int, Touch> touches = new Dictionary<int, Touch>(); // the touch fingerID (key) and the initial touch value.
     private float RotationX = 0f;
     private float RotationY = 0F;
  
     void Start()
     {
         RotationX = transform.eulerAngles.x;
         RotationY = transform.eulerAngles.y;        
     }
  
     void Update()
     {
         TouchControll();
     }
  
     void TouchControll() {
  
         foreach (Touch touch in Input.touches)
         {
             if (touch.phase == TouchPhase.Began)
             {
                 if (!touches.ContainsKey(touch.fingerId))
                     touches.Add(touch.fingerId, touch);
             }
             else if (touch.phase == TouchPhase.Moved)
             {
                 Touch initialTouch = touches[touch.fingerId];
                 float deltaX = touch.position.x - initialTouch.position.x;
                 float deltaY = touch.position.y - initialTouch.position.y;
                 RotationX += deltaX * Time.deltaTime * 0.08f;
                 RotationY += deltaY * Time.deltaTime * 0.08f * -1f;
                 transform.eulerAngles = new Vector3(RotationY, RotationX, 0f); // In portrait mode, swiping vertically = horizontal swipe in landscape mode. So rotY = x and rotX = y;
             }
             else if (touch.phase == TouchPhase.Ended)
             {
                 touches.Remove(touch.fingerId);
             }
         }
     }
 }

How can I improve this code in such way that It doesnt get all jittery/breaking?

Thank you in advance.