Primarily a way to save the game state
The past few years I've really been struggling with my world map and storing all sorts of nested data. (Locations that have array lists of units stored there, armies walking around with unique names that have unique unit lists... etc) and at first I used Player Prefs, but it was super limiting, quiiiickly jumped over to Easy Save, but I was having to build a ton of initialization checks for the data, so instead I then ported everything over to Game Data Editor which has been great, but from the way I hear people talk about serialization it just sounds like exactly what I'm looking for.
Granted this is without me
really understanding how it would fit in a Playmaker context. But the way I envision it is if scenes loaded with whatever prior variables were set to the last time it was open, that would be fantastic