One definition of micromanagement is how many repetitions of that decision/action are you doing? If you have to do something every turn or for every pop you have, it's terrible MM. If you do it rarely, then its not MM.
So going through your cities every turn and making sure that each pop is working the optimal tile is terrible MM. Not so much of that in Civ6 (just check when a city grows at most), but in older Civs it was terrible, having to assign entertainers every turn to prevent riots was a colossal waste of time.
Changing civics happens at the "empire" level - so no repetition there - but does have to be done every ~10 turns. Can get tiresome.
Assigning production to cities happens every ~20 turns, but is per city. In the large game this can become the most time consuming task each turn. Bad MM.
Moving units while at war is bad MM: it has to be done for every unit and every turn. However, when it comes to actual fighting (rather than moving to the front line) each action requires serious thought rather than bland repetition.
Picking techs and civics to research is no MM. You do each once every 10 turns, and almost every time its substantially different.
