Argument for top: Toplaners scale/snowball best given they can get to level 20, so the earlier they can join the rest of the map the better.
Argument for mid: It opens up the map for your team allowing easier access to get safe vision and secure objectives.
Argument for bot: It allows your botlane (2 players) to come mid earlier and apply more pressure on the map.
Is there available data anywhere on this?