Android Async Handler Difference

MainActivity.kt

package com.codingblocks.handlerasync

import android.annotation.SuppressLint
import android.os.Bundle
import android.os.Handler
import android.os.Looper
import android.util.Log
import androidx.appcompat.app.AppCompatActivity
import kotlinx.android.synthetic.main.activity_main.*

class MainActivity : AppCompatActivity() {

    @SuppressLint("NewApi")
    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_main)

        val start = System.currentTimeMillis()
        var curr = start
        var delta = 0L
        var delay = 0L

        val h = Handler.createAsync(Looper.myLooper())
//        val h = Handler()

        repeat(100) { i ->
            h.postDelayed({
                delta = System.currentTimeMillis() - curr
                curr += delta
                delay = curr - start
                Log.d(
                    "TIME",
                    "iteration = $i, delay = $delay, delta = $delta text = ${myTextView.text}"
                )
            }, i * 5L)
        }
        repeat(100) { i ->
            h.postDelayed({
                myTextView.text = delay.toString()
            }, i * 5L)
        }

    }
}