Effective learning occurs when you're challenging yourself appropriately. Make a task too easy and it's boring, make it too hard and you quit. This feature would help aspiring learners to master the game quicker by giving them locations of appropriate difficulty as opposed to random distribution.

In Practice mode (in the same menu as Singleplayer and Challenge) you can choose the difficulty of locations you'll receive on a map. Location difficulty is assigned by an algorithm, this has been done by the devs already – rank locations based on how many people got them right and at which rating: https://www.geoguessr.com/maps/66c88417836032cf1fb220dd