Define default corrutine for filter operation

Android
1
  1. If i have function with want DB or Net usage + many list manupulation. I must alltime change cotext to IO /. Default
    2/ If i use corrutines in Main thread and want to filter big collection i can use “collection.fillter.map.forEach {UITHreadFunc Or not i do’t want reseach each ttime}”. In main thread its slow down, in default i can get exceptuion.
    Why we dont use Executors.Default for all collection operaion (except function body execution) if for context now is Default.Main? It’s will be great smart feature