is coroutines necessary in kotlin code example

Example: kotlin coroutines

import kotlinx.coroutines.*
// Asynchronous execution
fun main() {
  GlobalScope.launch { 	// creates a new coroutine and continues
    doWorld()			// suspending function
  }
  println("World !") 	// execution continues even while coroutine waits
  runBlocking { 		// block main thread for 4 s (waits for 1rst coroutine)
  	delay(4000L) 		
  }
}
suspend fun doWorld() {
  delay(2000L) 		// non-blocking delay for 2000 milliseconds
  println("Hello")	// printed after "World !"
}