POST /history/task API vs GET /history/task

My question is why there are 2 APIs for getting tasks in camunda?
What was the reason POST verb created ?

Is there documentation which explains why we should go for GET /task instead of above 2 APIs as historic also contains active tasks?

As explained in the documnetation, post allows filtering by multiple process or task variables of types String , Number or Boolean.

You can do this, but this will perform unnecessary queries on the history tables and reduce performance